Python从用户读取单个字符

问题:Python从用户读取单个字符

有没有一种方法可以从用户输入中读取单个字符?例如,他们在终端上按一个键,然后将其返回(类似getch())。我知道Windows中有一个功能,但是我想要跨平台的功能。

Is there a way of reading one single character from the user input? For instance, they press one key at the terminal and it is returned (sort of like getch()). I know there’s a function in Windows for it, but I’d like something that is cross-platform.


回答 0

以下是指向该站点的链接,该站点说明了如何在Windows,Linux和OSX中读取单个字符:http : //code.activestate.com/recipes/134892/

class _Getch:
    """Gets a single character from standard input.  Does not echo to the
screen."""
    def __init__(self):
        try:
            self.impl = _GetchWindows()
        except ImportError:
            self.impl = _GetchUnix()

    def __call__(self): return self.impl()


class _GetchUnix:
    def __init__(self):
        import tty, sys

    def __call__(self):
        import sys, tty, termios
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)
        try:
            tty.setraw(sys.stdin.fileno())
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch


class _GetchWindows:
    def __init__(self):
        import msvcrt

    def __call__(self):
        import msvcrt
        return msvcrt.getch()


getch = _Getch()

Here’s a link to a site that says how you can read a single character in Windows, Linux and OSX: http://code.activestate.com/recipes/134892/

class _Getch:
    """Gets a single character from standard input.  Does not echo to the
screen."""
    def __init__(self):
        try:
            self.impl = _GetchWindows()
        except ImportError:
            self.impl = _GetchUnix()

    def __call__(self): return self.impl()


class _GetchUnix:
    def __init__(self):
        import tty, sys

    def __call__(self):
        import sys, tty, termios
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)
        try:
            tty.setraw(sys.stdin.fileno())
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch


class _GetchWindows:
    def __init__(self):
        import msvcrt

    def __call__(self):
        import msvcrt
        return msvcrt.getch()


getch = _Getch()

回答 1

sys.stdin.read(1)

基本上将从STDIN读取1个字节。

如果必须使用不等待的方法,则\n可以按照先前答案中的建议使用此代码:

class _Getch:
    """Gets a single character from standard input.  Does not echo to the screen."""
    def __init__(self):
        try:
            self.impl = _GetchWindows()
        except ImportError:
            self.impl = _GetchUnix()

    def __call__(self): return self.impl()


class _GetchUnix:
    def __init__(self):
        import tty, sys

    def __call__(self):
        import sys, tty, termios
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)
        try:
            tty.setraw(sys.stdin.fileno())
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch


class _GetchWindows:
    def __init__(self):
        import msvcrt

    def __call__(self):
        import msvcrt
        return msvcrt.getch()


getch = _Getch()

摘自 http://code.activestate.com/recipes/134892/

sys.stdin.read(1)

will basically read 1 byte from STDIN.

If you must use the method which does not wait for the \n you can use this code as suggested in previous answer:

class _Getch:
    """Gets a single character from standard input.  Does not echo to the screen."""
    def __init__(self):
        try:
            self.impl = _GetchWindows()
        except ImportError:
            self.impl = _GetchUnix()

    def __call__(self): return self.impl()


class _GetchUnix:
    def __init__(self):
        import tty, sys

    def __call__(self):
        import sys, tty, termios
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)
        try:
            tty.setraw(sys.stdin.fileno())
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch


class _GetchWindows:
    def __init__(self):
        import msvcrt

    def __call__(self):
        import msvcrt
        return msvcrt.getch()


getch = _Getch()

(taken from http://code.activestate.com/recipes/134892/)


回答 2

在两个答案中逐字引用的ActiveState 配方经过了精心设计。可以归结为:

def _find_getch():
    try:
        import termios
    except ImportError:
        # Non-POSIX. Return msvcrt's (Windows') getch.
        import msvcrt
        return msvcrt.getch

    # POSIX system. Create and return a getch that manipulates the tty.
    import sys, tty
    def _getch():
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)
        try:
            tty.setraw(fd)
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch

    return _getch

getch = _find_getch()

The ActiveState recipe quoted verbatim in two answers is over-engineered. It can be boiled down to this:

def _find_getch():
    try:
        import termios
    except ImportError:
        # Non-POSIX. Return msvcrt's (Windows') getch.
        import msvcrt
        return msvcrt.getch

    # POSIX system. Create and return a getch that manipulates the tty.
    import sys, tty
    def _getch():
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)
        try:
            tty.setraw(fd)
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch

    return _getch

getch = _find_getch()

回答 3

还值得尝试的是readchar库,该库部分基于其他答案中提到的ActiveState配方。

安装:

pip install readchar

用法:

import readchar
print("Reading a char:")
print(repr(readchar.readchar()))
print("Reading a key:")
print(repr(readchar.readkey()))

在Windows和Linux上使用Python 2.7进行了测试。

在Windows上,只有映射到字母或ASCII控制代码键的支持(BackspaceEnterEscTabCtrl+ 字母)。在GNU / Linux(取决于具体终端上,也许?),你也可以得到InsertDeletePg UpPg DnHomeEnd和键…但随后,有分离的这些特殊键问题。F nEsc

警告:像这里的大多数(全部?)答案一样,信号键(如Ctrl+ CCtrl+ DCtrl+)Z被捕获并返回(分别为'\x03''\x04''\x1a');您的程序可能很难终止。

Also worth trying is the readchar library, which is in part based on the ActiveState recipe mentioned in other answers.

Installation:

pip install readchar

Usage:

import readchar
print("Reading a char:")
print(repr(readchar.readchar()))
print("Reading a key:")
print(repr(readchar.readkey()))

Tested on Windows and Linux with Python 2.7.

On Windows, only keys which map to letters or ASCII control codes are supported (Backspace, Enter, Esc, Tab, Ctrl+letter). On GNU/Linux (depending on exact terminal, perhaps?) you also get Insert, Delete, Pg Up, Pg Dn, Home, End and F n keys… but then, there’s issues separating these special keys from an Esc.

Caveat: Like with most (all?) answers in here, signal keys like Ctrl+C, Ctrl+D and Ctrl+Z are caught and returned (as '\x03', '\x04' and '\x1a' respectively); your program can be come difficult to abort.


回答 4

替代方法:

import os
import sys    
import termios
import fcntl

def getch():
  fd = sys.stdin.fileno()

  oldterm = termios.tcgetattr(fd)
  newattr = termios.tcgetattr(fd)
  newattr[3] = newattr[3] & ~termios.ICANON & ~termios.ECHO
  termios.tcsetattr(fd, termios.TCSANOW, newattr)

  oldflags = fcntl.fcntl(fd, fcntl.F_GETFL)
  fcntl.fcntl(fd, fcntl.F_SETFL, oldflags | os.O_NONBLOCK)

  try:        
    while 1:            
      try:
        c = sys.stdin.read(1)
        break
      except IOError: pass
  finally:
    termios.tcsetattr(fd, termios.TCSAFLUSH, oldterm)
    fcntl.fcntl(fd, fcntl.F_SETFL, oldflags)
  return c

这篇博客文章中

An alternative method:

import os
import sys    
import termios
import fcntl

def getch():
  fd = sys.stdin.fileno()

  oldterm = termios.tcgetattr(fd)
  newattr = termios.tcgetattr(fd)
  newattr[3] = newattr[3] & ~termios.ICANON & ~termios.ECHO
  termios.tcsetattr(fd, termios.TCSANOW, newattr)

  oldflags = fcntl.fcntl(fd, fcntl.F_GETFL)
  fcntl.fcntl(fd, fcntl.F_SETFL, oldflags | os.O_NONBLOCK)

  try:        
    while 1:            
      try:
        c = sys.stdin.read(1)
        break
      except IOError: pass
  finally:
    termios.tcsetattr(fd, termios.TCSAFLUSH, oldterm)
    fcntl.fcntl(fd, fcntl.F_SETFL, oldflags)
  return c

From this blog post.


回答 5

如果按+ 或+ ,则此代码基于此处,将正确引发KeyboardInterrupt和EOFError 。CtrlCCtrlD

应该可以在Windows和Linux上使用。可从原始来源获得OS X版本。

class _Getch:
    """Gets a single character from standard input.  Does not echo to the screen."""
    def __init__(self):
        try:
            self.impl = _GetchWindows()
        except ImportError:
            self.impl = _GetchUnix()

    def __call__(self): 
        char = self.impl()
        if char == '\x03':
            raise KeyboardInterrupt
        elif char == '\x04':
            raise EOFError
        return char

class _GetchUnix:
    def __init__(self):
        import tty
        import sys

    def __call__(self):
        import sys
        import tty
        import termios
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)
        try:
            tty.setraw(sys.stdin.fileno())
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch


class _GetchWindows:
    def __init__(self):
        import msvcrt

    def __call__(self):
        import msvcrt
        return msvcrt.getch()


getch = _Getch()

This code, based off here, will correctly raise KeyboardInterrupt and EOFError if Ctrl+C or Ctrl+D are pressed.

Should work on Windows and Linux. An OS X version is available from the original source.

class _Getch:
    """Gets a single character from standard input.  Does not echo to the screen."""
    def __init__(self):
        try:
            self.impl = _GetchWindows()
        except ImportError:
            self.impl = _GetchUnix()

    def __call__(self): 
        char = self.impl()
        if char == '\x03':
            raise KeyboardInterrupt
        elif char == '\x04':
            raise EOFError
        return char

class _GetchUnix:
    def __init__(self):
        import tty
        import sys

    def __call__(self):
        import sys
        import tty
        import termios
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)
        try:
            tty.setraw(sys.stdin.fileno())
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch


class _GetchWindows:
    def __init__(self):
        import msvcrt

    def __call__(self):
        import msvcrt
        return msvcrt.getch()


getch = _Getch()

回答 6

(当前)排名靠前的答案(带有ActiveState代码)过于复杂。当仅一个函数就足够时,我看不出使用类的理由。以下是两个实现相同功能但具有更易读代码的实现。

这两种实现:

  1. 在Python 2或Python 3中工作正常
  2. 在Windows,OSX和Linux上工作
  3. 只读取一个字节(即,他们不等待换行符)
  4. 不依赖任何外部库
  5. 是自包含的(函数定义之外没有代码)

版本1:可读又简单

def getChar():
    try:
        # for Windows-based systems
        import msvcrt # If successful, we are on Windows
        return msvcrt.getch()

    except ImportError:
        # for POSIX-based systems (with termios & tty support)
        import tty, sys, termios  # raises ImportError if unsupported

        fd = sys.stdin.fileno()
        oldSettings = termios.tcgetattr(fd)

        try:
            tty.setcbreak(fd)
            answer = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, oldSettings)

        return answer

版本2:避免重复导入和异常处理:

[编辑]我错过了ActiveState代码的一项优势。如果您打算多次读取字符,则该代码避免了在类似Unix的系统上重复执行Windows导入和ImportError异常处理的(可忽略的)成本。尽管您可能应该更关注代码的可读性而不是可以忽略的优化,但这是一种替代方法(它与Louis的答案类似,但是getChar()是自包含的),其功能与ActiveState代码相同,并且更具可读性:

def getChar():
    # figure out which function to use once, and store it in _func
    if "_func" not in getChar.__dict__:
        try:
            # for Windows-based systems
            import msvcrt # If successful, we are on Windows
            getChar._func=msvcrt.getch

        except ImportError:
            # for POSIX-based systems (with termios & tty support)
            import tty, sys, termios # raises ImportError if unsupported

            def _ttyRead():
                fd = sys.stdin.fileno()
                oldSettings = termios.tcgetattr(fd)

                try:
                    tty.setcbreak(fd)
                    answer = sys.stdin.read(1)
                finally:
                    termios.tcsetattr(fd, termios.TCSADRAIN, oldSettings)

                return answer

            getChar._func=_ttyRead

    return getChar._func()

上面的两个getChar()版本的示例代码:

from __future__ import print_function # put at top of file if using Python 2

# Example of a prompt for one character of input
promptStr   = "Please give me a character:"
responseStr = "Thank you for giving me a '{}'."
print(promptStr, end="\n> ")
answer = getChar()
print("\n")
print(responseStr.format(answer))

The (currently) top-ranked answer (with the ActiveState code) is overly complicated. I don’t see a reason to use classes when a mere function should suffice. Below are two implementations that accomplish the same thing but with more readable code.

Both of these implementations:

  1. work just fine in Python 2 or Python 3
  2. work on Windows, OSX, and Linux
  3. read just one byte (i.e., they don’t wait for a newline)
  4. don’t depend on any external libraries
  5. are self-contained (no code outside of the function definition)

Version 1: readable and simple

def getChar():
    try:
        # for Windows-based systems
        import msvcrt # If successful, we are on Windows
        return msvcrt.getch()

    except ImportError:
        # for POSIX-based systems (with termios & tty support)
        import tty, sys, termios  # raises ImportError if unsupported

        fd = sys.stdin.fileno()
        oldSettings = termios.tcgetattr(fd)

        try:
            tty.setcbreak(fd)
            answer = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, oldSettings)

        return answer

Version 2: avoid repeated imports and exception handling:

[EDIT] I missed one advantage of the ActiveState code. If you plan to read characters multiple times, that code avoids the (negligible) cost of repeating the Windows import and the ImportError exception handling on Unix-like systems. While you probably should be more concerned about code readability than that negligible optimization, here is an alternative (it is similar to Louis’s answer, but getChar() is self-contained) that functions the same as the ActiveState code and is more readable:

def getChar():
    # figure out which function to use once, and store it in _func
    if "_func" not in getChar.__dict__:
        try:
            # for Windows-based systems
            import msvcrt # If successful, we are on Windows
            getChar._func=msvcrt.getch

        except ImportError:
            # for POSIX-based systems (with termios & tty support)
            import tty, sys, termios # raises ImportError if unsupported

            def _ttyRead():
                fd = sys.stdin.fileno()
                oldSettings = termios.tcgetattr(fd)

                try:
                    tty.setcbreak(fd)
                    answer = sys.stdin.read(1)
                finally:
                    termios.tcsetattr(fd, termios.TCSADRAIN, oldSettings)

                return answer

            getChar._func=_ttyRead

    return getChar._func()

Example code that exercises either of the getChar() versions above:

from __future__ import print_function # put at top of file if using Python 2

# Example of a prompt for one character of input
promptStr   = "Please give me a character:"
responseStr = "Thank you for giving me a '{}'."
print(promptStr, end="\n> ")
answer = getChar()
print("\n")
print(responseStr.format(answer))

回答 7

这可能是上下文管理器的用例。撇开Windows操作系统的津贴,这是我的建议:

#!/usr/bin/env python3
# file: 'readchar.py'
"""
Implementation of a way to get a single character of input
without waiting for the user to hit <Enter>.
(OS is Linux, Ubuntu 14.04)
"""

import tty, sys, termios

class ReadChar():
    def __enter__(self):
        self.fd = sys.stdin.fileno()
        self.old_settings = termios.tcgetattr(self.fd)
        tty.setraw(sys.stdin.fileno())
        return sys.stdin.read(1)
    def __exit__(self, type, value, traceback):
        termios.tcsetattr(self.fd, termios.TCSADRAIN, self.old_settings)

def test():
    while True:
        with ReadChar() as rc:
            char = rc
        if ord(char) <= 32:
            print("You entered character with ordinal {}."\
                        .format(ord(char)))
        else:
            print("You entered character '{}'."\
                        .format(char))
        if char in "^C^D":
            sys.exit()

if __name__ == "__main__":
    test()

This might be a use case for a context manager. Leaving aside allowances for Windows OS, here’s my suggestion:

#!/usr/bin/env python3
# file: 'readchar.py'
"""
Implementation of a way to get a single character of input
without waiting for the user to hit <Enter>.
(OS is Linux, Ubuntu 14.04)
"""

import tty, sys, termios

class ReadChar():
    def __enter__(self):
        self.fd = sys.stdin.fileno()
        self.old_settings = termios.tcgetattr(self.fd)
        tty.setraw(sys.stdin.fileno())
        return sys.stdin.read(1)
    def __exit__(self, type, value, traceback):
        termios.tcsetattr(self.fd, termios.TCSADRAIN, self.old_settings)

def test():
    while True:
        with ReadChar() as rc:
            char = rc
        if ord(char) <= 32:
            print("You entered character with ordinal {}."\
                        .format(ord(char)))
        else:
            print("You entered character '{}'."\
                        .format(char))
        if char in "^C^D":
            sys.exit()

if __name__ == "__main__":
    test()

回答 8

尝试使用以下方法:http : //home.wlu.edu/~levys/software/kbhit.py 它是非阻塞的(这意味着您可以进行while循环并检测按键而无需停止它)和跨平台。

import os

# Windows
if os.name == 'nt':
    import msvcrt

# Posix (Linux, OS X)
else:
    import sys
    import termios
    import atexit
    from select import select


class KBHit:

    def __init__(self):
        '''Creates a KBHit object that you can call to do various keyboard things.'''

        if os.name == 'nt':
            pass

        else:

            # Save the terminal settings
            self.fd = sys.stdin.fileno()
            self.new_term = termios.tcgetattr(self.fd)
            self.old_term = termios.tcgetattr(self.fd)

            # New terminal setting unbuffered
            self.new_term[3] = (self.new_term[3] & ~termios.ICANON & ~termios.ECHO)
            termios.tcsetattr(self.fd, termios.TCSAFLUSH, self.new_term)

            # Support normal-terminal reset at exit
            atexit.register(self.set_normal_term)


    def set_normal_term(self):
        ''' Resets to normal terminal.  On Windows this is a no-op.
        '''

        if os.name == 'nt':
            pass

        else:
            termios.tcsetattr(self.fd, termios.TCSAFLUSH, self.old_term)


    def getch(self):
        ''' Returns a keyboard character after kbhit() has been called.
            Should not be called in the same program as getarrow().
        '''

        s = ''

        if os.name == 'nt':
            return msvcrt.getch().decode('utf-8')

        else:
            return sys.stdin.read(1)


    def getarrow(self):
        ''' Returns an arrow-key code after kbhit() has been called. Codes are
        0 : up
        1 : right
        2 : down
        3 : left
        Should not be called in the same program as getch().
        '''

        if os.name == 'nt':
            msvcrt.getch() # skip 0xE0
            c = msvcrt.getch()
            vals = [72, 77, 80, 75]

        else:
            c = sys.stdin.read(3)[2]
            vals = [65, 67, 66, 68]

        return vals.index(ord(c.decode('utf-8')))


    def kbhit(self):
        ''' Returns True if keyboard character was hit, False otherwise.
        '''
        if os.name == 'nt':
            return msvcrt.kbhit()

        else:
            dr,dw,de = select([sys.stdin], [], [], 0)
            return dr != []

使用此示例:

import kbhit

kb = kbhit.KBHit()

while(True): 
    print("Key not pressed") #Do something
    if kb.kbhit(): #If a key is pressed:
        k_in = kb.getch() #Detect what key was pressed
        print("You pressed ", k_in, "!") #Do something
kb.set_normal_term()

或者您可以使用PyPigetch模块。但这会阻塞while循环

Try using this: http://home.wlu.edu/~levys/software/kbhit.py It’s non-blocking (that means that you can have a while loop and detect a key press without stopping it) and cross-platform.

import os

# Windows
if os.name == 'nt':
    import msvcrt

# Posix (Linux, OS X)
else:
    import sys
    import termios
    import atexit
    from select import select


class KBHit:

    def __init__(self):
        '''Creates a KBHit object that you can call to do various keyboard things.'''

        if os.name == 'nt':
            pass

        else:

            # Save the terminal settings
            self.fd = sys.stdin.fileno()
            self.new_term = termios.tcgetattr(self.fd)
            self.old_term = termios.tcgetattr(self.fd)

            # New terminal setting unbuffered
            self.new_term[3] = (self.new_term[3] & ~termios.ICANON & ~termios.ECHO)
            termios.tcsetattr(self.fd, termios.TCSAFLUSH, self.new_term)

            # Support normal-terminal reset at exit
            atexit.register(self.set_normal_term)


    def set_normal_term(self):
        ''' Resets to normal terminal.  On Windows this is a no-op.
        '''

        if os.name == 'nt':
            pass

        else:
            termios.tcsetattr(self.fd, termios.TCSAFLUSH, self.old_term)


    def getch(self):
        ''' Returns a keyboard character after kbhit() has been called.
            Should not be called in the same program as getarrow().
        '''

        s = ''

        if os.name == 'nt':
            return msvcrt.getch().decode('utf-8')

        else:
            return sys.stdin.read(1)


    def getarrow(self):
        ''' Returns an arrow-key code after kbhit() has been called. Codes are
        0 : up
        1 : right
        2 : down
        3 : left
        Should not be called in the same program as getch().
        '''

        if os.name == 'nt':
            msvcrt.getch() # skip 0xE0
            c = msvcrt.getch()
            vals = [72, 77, 80, 75]

        else:
            c = sys.stdin.read(3)[2]
            vals = [65, 67, 66, 68]

        return vals.index(ord(c.decode('utf-8')))


    def kbhit(self):
        ''' Returns True if keyboard character was hit, False otherwise.
        '''
        if os.name == 'nt':
            return msvcrt.kbhit()

        else:
            dr,dw,de = select([sys.stdin], [], [], 0)
            return dr != []

An example to use this:

import kbhit

kb = kbhit.KBHit()

while(True): 
    print("Key not pressed") #Do something
    if kb.kbhit(): #If a key is pressed:
        k_in = kb.getch() #Detect what key was pressed
        print("You pressed ", k_in, "!") #Do something
kb.set_normal_term()

Or you could use the getch module from PyPi. But this would block the while loop


回答 9

这是NON-BLOCKING,它读取一个密钥并将其存储在keypress.key中。

import Tkinter as tk


class Keypress:
    def __init__(self):
        self.root = tk.Tk()
        self.root.geometry('300x200')
        self.root.bind('<KeyPress>', self.onKeyPress)

    def onKeyPress(self, event):
        self.key = event.char

    def __eq__(self, other):
        return self.key == other

    def __str__(self):
        return self.key

在您的程序中

keypress = Keypress()

while something:
   do something
   if keypress == 'c':
        break
   elif keypress == 'i': 
       print('info')
   else:
       print("i dont understand %s" % keypress)

This is NON-BLOCKING, reads a key and and stores it in keypress.key.

import Tkinter as tk


class Keypress:
    def __init__(self):
        self.root = tk.Tk()
        self.root.geometry('300x200')
        self.root.bind('<KeyPress>', self.onKeyPress)

    def onKeyPress(self, event):
        self.key = event.char

    def __eq__(self, other):
        return self.key == other

    def __str__(self):
        return self.key

in your programm

keypress = Keypress()

while something:
   do something
   if keypress == 'c':
        break
   elif keypress == 'i': 
       print('info')
   else:
       print("i dont understand %s" % keypress)

回答 10

此处的答案是有益的,但是我还想一种方法来异步获取按键并在单独的事件中触发按键,所有这些操作都是以线程安全的,跨平台的方式进行的。PyGame对我来说也太肿。因此,我做了以下工作(在Python 2.7中,但我怀疑它很容易移植),我想在这里分享一下,以防对其他人有用。我将其存储在名为keyPress.py的文件中。

class _Getch:
    """Gets a single character from standard input.  Does not echo to the
screen. From http://code.activestate.com/recipes/134892/"""
    def __init__(self):
        try:
            self.impl = _GetchWindows()
        except ImportError:
            try:
                self.impl = _GetchMacCarbon()
            except(AttributeError, ImportError):
                self.impl = _GetchUnix()

    def __call__(self): return self.impl()


class _GetchUnix:
    def __init__(self):
        import tty, sys, termios # import termios now or else you'll get the Unix version on the Mac

    def __call__(self):
        import sys, tty, termios
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)
        try:
            tty.setraw(sys.stdin.fileno())
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch

class _GetchWindows:
    def __init__(self):
        import msvcrt

    def __call__(self):
        import msvcrt
        return msvcrt.getch()

class _GetchMacCarbon:
    """
    A function which returns the current ASCII key that is down;
    if no ASCII key is down, the null string is returned.  The
    page http://www.mactech.com/macintosh-c/chap02-1.html was
    very helpful in figuring out how to do this.
    """
    def __init__(self):
        import Carbon
        Carbon.Evt #see if it has this (in Unix, it doesn't)

    def __call__(self):
        import Carbon
        if Carbon.Evt.EventAvail(0x0008)[0]==0: # 0x0008 is the keyDownMask
            return ''
        else:
            #
            # The event contains the following info:
            # (what,msg,when,where,mod)=Carbon.Evt.GetNextEvent(0x0008)[1]
            #
            # The message (msg) contains the ASCII char which is
            # extracted with the 0x000000FF charCodeMask; this
            # number is converted to an ASCII character with chr() and
            # returned
            #
            (what,msg,when,where,mod)=Carbon.Evt.GetNextEvent(0x0008)[1]
            return chr(msg & 0x000000FF)

import threading


# From  https://stackoverflow.com/a/2022629/2924421
class Event(list):
    def __call__(self, *args, **kwargs):
        for f in self:
            f(*args, **kwargs)

    def __repr__(self):
        return "Event(%s)" % list.__repr__(self)            


def getKey():
    inkey = _Getch()
    import sys
    for i in xrange(sys.maxint):
        k=inkey()
        if k<>'':break
    return k

class KeyCallbackFunction():
    callbackParam = None
    actualFunction = None

    def __init__(self, actualFunction, callbackParam):
        self.actualFunction = actualFunction
        self.callbackParam = callbackParam

    def doCallback(self, inputKey):
        if not self.actualFunction is None:
            if self.callbackParam is None:
                callbackFunctionThread = threading.Thread(target=self.actualFunction, args=(inputKey,))
            else:
                callbackFunctionThread = threading.Thread(target=self.actualFunction, args=(inputKey,self.callbackParam))

            callbackFunctionThread.daemon = True
            callbackFunctionThread.start()



class KeyCapture():


    gotKeyLock = threading.Lock()
    gotKeys = []
    gotKeyEvent = threading.Event()

    keyBlockingSetKeyLock = threading.Lock()

    addingEventsLock = threading.Lock()
    keyReceiveEvents = Event()


    keysGotLock = threading.Lock()
    keysGot = []

    keyBlockingKeyLockLossy = threading.Lock()
    keyBlockingKeyLossy = None
    keyBlockingEventLossy = threading.Event()

    keysBlockingGotLock = threading.Lock()
    keysBlockingGot = []
    keyBlockingGotEvent = threading.Event()



    wantToStopLock = threading.Lock()
    wantToStop = False

    stoppedLock = threading.Lock()
    stopped = True

    isRunningEvent = False

    getKeyThread = None

    keyFunction = None
    keyArgs = None

    # Begin capturing keys. A seperate thread is launched that
    # captures key presses, and then these can be received via get,
    # getAsync, and adding an event via addEvent. Note that this
    # will prevent the system to accept keys as normal (say, if
    # you are in a python shell) because it overrides that key
    # capturing behavior.

    # If you start capture when it's already been started, a
    # InterruptedError("Keys are still being captured")
    # will be thrown

    # Note that get(), getAsync() and events are independent, so if a key is pressed:
    #
    # 1: Any calls to get() that are waiting, with lossy on, will return
    #    that key
    # 2: It will be stored in the queue of get keys, so that get() with lossy
    #    off will return the oldest key pressed not returned by get() yet.
    # 3: All events will be fired with that key as their input
    # 4: It will be stored in the list of getAsync() keys, where that list
    #    will be returned and set to empty list on the next call to getAsync().
    # get() call with it, aand add it to the getAsync() list.
    def startCapture(self, keyFunction=None, args=None):
        # Make sure we aren't already capturing keys
        self.stoppedLock.acquire()
        if not self.stopped:
            self.stoppedLock.release()
            raise InterruptedError("Keys are still being captured")
            return
        self.stopped = False
        self.stoppedLock.release()

        # If we have captured before, we need to allow the get() calls to actually
        # wait for key presses now by clearing the event
        if self.keyBlockingEventLossy.is_set():
            self.keyBlockingEventLossy.clear()

        # Have one function that we call every time a key is captured, intended for stopping capture
        # as desired
        self.keyFunction = keyFunction
        self.keyArgs = args

        # Begin capturing keys (in a seperate thread)
        self.getKeyThread = threading.Thread(target=self._threadProcessKeyPresses)
        self.getKeyThread.daemon = True
        self.getKeyThread.start()

        # Process key captures (in a seperate thread)
        self.getKeyThread = threading.Thread(target=self._threadStoreKeyPresses)
        self.getKeyThread.daemon = True
        self.getKeyThread.start()


    def capturing(self):
        self.stoppedLock.acquire()
        isCapturing = not self.stopped
        self.stoppedLock.release()
        return isCapturing
    # Stops the thread that is capturing keys on the first opporunity
    # has to do so. It usually can't stop immediately because getting a key
    # is a blocking process, so this will probably stop capturing after the
    # next key is pressed.
    #
    # However, Sometimes if you call stopCapture it will stop before starting capturing the
    # next key, due to multithreading race conditions. So if you want to stop capturing
    # reliably, call stopCapture in a function added via addEvent. Then you are
    # guaranteed that capturing will stop immediately after the rest of the callback
    # functions are called (before starting to capture the next key).
    def stopCapture(self):
        self.wantToStopLock.acquire()
        self.wantToStop = True 
        self.wantToStopLock.release()

    # Takes in a function that will be called every time a key is pressed (with that
    # key passed in as the first paramater in that function)
    def addEvent(self, keyPressEventFunction, args=None):   
        self.addingEventsLock.acquire()
        callbackHolder = KeyCallbackFunction(keyPressEventFunction, args)
        self.keyReceiveEvents.append(callbackHolder.doCallback)
        self.addingEventsLock.release()
    def clearEvents(self):
        self.addingEventsLock.acquire()
        self.keyReceiveEvents = Event()
        self.addingEventsLock.release()
    # Gets a key captured by this KeyCapture, blocking until a key is pressed.
    # There is an optional lossy paramater:
    # If True all keys before this call are ignored, and the next pressed key
    #   will be returned.
    # If False this will return the oldest key captured that hasn't
    #   been returned by get yet. False is the default.
    def get(self, lossy=False):
        if lossy:
            # Wait for the next key to be pressed
            self.keyBlockingEventLossy.wait()
            self.keyBlockingKeyLockLossy.acquire()
            keyReceived = self.keyBlockingKeyLossy
            self.keyBlockingKeyLockLossy.release()
            return keyReceived
        else:
            while True:
                # Wait until a key is pressed
                self.keyBlockingGotEvent.wait()

                # Get the key pressed
                readKey = None
                self.keysBlockingGotLock.acquire()
                # Get a key if it exists
                if len(self.keysBlockingGot) != 0:
                    readKey = self.keysBlockingGot.pop(0)
                # If we got the last one, tell us to wait
                if len(self.keysBlockingGot) == 0:
                    self.keyBlockingGotEvent.clear()
                self.keysBlockingGotLock.release()

                # Process the key (if it actually exists)
                if not readKey is None:
                    return readKey

                # Exit if we are stopping
                self.wantToStopLock.acquire()
                if self.wantToStop:
                    self.wantToStopLock.release()
                    return None
                self.wantToStopLock.release()




    def clearGetList(self):
        self.keysBlockingGotLock.acquire()
        self.keysBlockingGot = []
        self.keysBlockingGotLock.release()

    # Gets a list of all keys pressed since the last call to getAsync, in order
    # from first pressed, second pressed, .., most recent pressed
    def getAsync(self):
        self.keysGotLock.acquire();
        keysPressedList = list(self.keysGot)
        self.keysGot = []
        self.keysGotLock.release()
        return keysPressedList

    def clearAsyncList(self):
        self.keysGotLock.acquire();
        self.keysGot = []
        self.keysGotLock.release();

    def _processKey(self, readKey):
        # Append to list for GetKeyAsync
        self.keysGotLock.acquire()
        self.keysGot.append(readKey)
        self.keysGotLock.release()

        # Call lossy blocking key events
        self.keyBlockingKeyLockLossy.acquire()
        self.keyBlockingKeyLossy = readKey
        self.keyBlockingEventLossy.set()
        self.keyBlockingEventLossy.clear()
        self.keyBlockingKeyLockLossy.release()

        # Call non-lossy blocking key events
        self.keysBlockingGotLock.acquire()
        self.keysBlockingGot.append(readKey)
        if len(self.keysBlockingGot) == 1:
            self.keyBlockingGotEvent.set()
        self.keysBlockingGotLock.release()

        # Call events added by AddEvent
        self.addingEventsLock.acquire()
        self.keyReceiveEvents(readKey)
        self.addingEventsLock.release()

    def _threadProcessKeyPresses(self):
        while True:
            # Wait until a key is pressed
            self.gotKeyEvent.wait()

            # Get the key pressed
            readKey = None
            self.gotKeyLock.acquire()
            # Get a key if it exists
            if len(self.gotKeys) != 0:
                readKey = self.gotKeys.pop(0)
            # If we got the last one, tell us to wait
            if len(self.gotKeys) == 0:
                self.gotKeyEvent.clear()
            self.gotKeyLock.release()

            # Process the key (if it actually exists)
            if not readKey is None:
                self._processKey(readKey)

            # Exit if we are stopping
            self.wantToStopLock.acquire()
            if self.wantToStop:
                self.wantToStopLock.release()
                break
            self.wantToStopLock.release()

    def _threadStoreKeyPresses(self):
        while True:
            # Get a key
            readKey = getKey()

            # Run the potential shut down function
            if not self.keyFunction is None:
                self.keyFunction(readKey, self.keyArgs)

            # Add the key to the list of pressed keys
            self.gotKeyLock.acquire()
            self.gotKeys.append(readKey)
            if len(self.gotKeys) == 1:
                self.gotKeyEvent.set()
            self.gotKeyLock.release()

            # Exit if we are stopping
            self.wantToStopLock.acquire()
            if self.wantToStop:
                self.wantToStopLock.release()
                self.gotKeyEvent.set()
                break
            self.wantToStopLock.release()


        # If we have reached here we stopped capturing

        # All we need to do to clean up is ensure that
        # all the calls to .get() now return None.
        # To ensure no calls are stuck never returning,
        # we will leave the event set so any tasks waiting
        # for it immediately exit. This will be unset upon
        # starting key capturing again.

        self.stoppedLock.acquire()

        # We also need to set this to True so we can start up
        # capturing again.
        self.stopped = True
        self.stopped = True

        self.keyBlockingKeyLockLossy.acquire()
        self.keyBlockingKeyLossy = None
        self.keyBlockingEventLossy.set()
        self.keyBlockingKeyLockLossy.release()

        self.keysBlockingGotLock.acquire()
        self.keyBlockingGotEvent.set()
        self.keysBlockingGotLock.release()

        self.stoppedLock.release()

这个想法是,您可以简单地调用keyPress.getKey(),它将从键盘读取一个键,然后将其返回。

如果您还想要更多,我做了一个KeyCapture对象。您可以通过类似的方式创建一个keys = keyPress.KeyCapture()

然后,您可以做三件事:

addEvent(functionName)接受具有一个参数的任何函数。然后,每次按下某个键时,将使用该键的字符串作为输入来调用此函数。它们在单独的线程中运行,因此您可以在其中阻塞所有所需的消息,并且不会弄乱KeyCapturer的功能,也不会延迟其他事件。

get()以与以前相同的阻塞方式返回键。现在需要在这里,因为密钥现在是通过KeyCapture对象捕获的,因此keyPress.getKey()会与该行为发生冲突,并且由于一次只能捕获一个密钥,因此它们都会丢失某些密钥。同样,假设用户按“ a”,然后按“ b”,即您叫get(),用户按“ c”。该get()调用将立即返回“ a”,然后再次调用它将返回“ b”,然后返回“ c”。如果再次调用它,它将阻塞直到按下另一个键。这样可以确保您不会遗漏任何按键,如果需要的话,可以采用阻塞方式。因此,这种方式keyPress.getKey()与以前有所不同

如果您想要getKey()返回的行为,get(lossy=True)则类似于get(),只是它仅返回在调用之后按下的键get()。因此,在上面的示例中,get()将阻塞直到用户按下“ c”,然后如果再次调用它,它将阻塞直到按下另一个键。

getAsync()有点不同。它是为需要大量处理的事物而设计的,然后偶尔返回并检查按下了哪些键。因此,按从最旧按键到最新按键的顺序getAsync()返回自上次调用以来所有按键的列表getAsync()。它也不会阻塞,这意味着如果自上次调用以来没有按键被按下getAsync()[]则将返回一个空 值。

要真正开始捕获键,您需要使用上面制作keys.startCapture()keys对象进行调用。startCapture是非阻塞的,只需启动一个仅记录按键操作的线程,然后启动另一个线程处理按键操作。有两个线程可确保记录按键的线程不会丢失任何按键。

如果要停止捕获密钥,可以拨打电话keys.stopCapture(),它将停止捕获密钥。但是,由于捕获键是一项阻塞操作,线程捕获键可能在调用后又捕获了一个键stopCapture()

为防止这种情况,您可以将一个可选参数传入 startCapture(functionName, args)一个函数,该函数仅执行类似的检查键是否等于“ c”然后退出。重要的是此功能在执行之前几乎不起作用,例如,在这里睡觉会导致我们错过按键。

但是,如果stopCapture()在此函数中调用,则键捕获将立即停止,而不再尝试捕获,并且所有get()调用将立即返回,如果尚未按下任何键,则返回None。

另外,由于get()getAsync()存储了所有先前按下的键(直到检索到它们),因此您可以调用clearGetList()clearAsyncList()忘记先前按下的键。

请注意get()getAsync()和事件是独立的,因此如果按下一个键:1 get().对该键的一个呼叫正在等待且有损打开,将返回该键。其他等待的呼叫(如果有)将继续等待。2.该密钥将存储在获取密钥的队列中,以便get()在有损关闭的情况下将返回get()尚未返回的最旧的密钥。3.将使用该键作为输入触发所有事件。4.该键将存储在getAsync()键列表中,该列表将返回并在下一次调用时设置为空列表。getAsync()

如果这一切都太多了,那么这里是一个用例示例:

import keyPress
import time
import threading

def KeyPressed(k, printLock):
    printLock.acquire()
    print "Event: " + k
    printLock.release()
    time.sleep(4)
    printLock.acquire()
    print "Event after delay: " + k
    printLock.release()

def GetKeyBlocking(keys, printLock):    
    while keys.capturing():
        keyReceived = keys.get()
        time.sleep(1)
        printLock.acquire()
        if not keyReceived is None:
            print "Block " + keyReceived
        else:
            print "Block None"
        printLock.release()

def GetKeyBlockingLossy(keys, printLock):   
    while keys.capturing():
        keyReceived = keys.get(lossy=True)
        time.sleep(1)
        printLock.acquire()
        if not keyReceived is None:
            print "Lossy: " + keyReceived
        else:
            print "Lossy: None"
        printLock.release()

def CheckToClose(k, (keys, printLock)):
    printLock.acquire()
    print "Close: " + k
    printLock.release()
    if k == "c":
        keys.stopCapture()

printLock = threading.Lock()

print "Press a key:"
print "You pressed: " + keyPress.getKey()
print ""

keys = keyPress.KeyCapture()

keys.addEvent(KeyPressed, printLock)



print "Starting capture"

keys.startCapture(CheckToClose, (keys, printLock))

getKeyBlockingThread = threading.Thread(target=GetKeyBlocking, args=(keys, printLock))
getKeyBlockingThread.daemon = True
getKeyBlockingThread.start()


getKeyBlockingThreadLossy = threading.Thread(target=GetKeyBlockingLossy, args=(keys, printLock))
getKeyBlockingThreadLossy.daemon = True
getKeyBlockingThreadLossy.start()

while keys.capturing():
    keysPressed = keys.getAsync()
    printLock.acquire()
    if keysPressed != []:
        print "Async: " + str(keysPressed)
    printLock.release()
    time.sleep(1)

print "done capturing"

从我进行的简单测试来看,这对我来说效果很好,但是如果我错过了一些事情,我也会很高兴也接受其他反馈。

我也张贴在这里

The answers here were informative, however I also wanted a way to get key presses asynchronously and fire off key presses in separate events, all in a thread-safe, cross-platform way. PyGame was also too bloated for me. So I made the following (in Python 2.7 but I suspect it’s easily portable), which I figured I’d share here in case it was useful for anyone else. I stored this in a file named keyPress.py.

class _Getch:
    """Gets a single character from standard input.  Does not echo to the
screen. From http://code.activestate.com/recipes/134892/"""
    def __init__(self):
        try:
            self.impl = _GetchWindows()
        except ImportError:
            try:
                self.impl = _GetchMacCarbon()
            except(AttributeError, ImportError):
                self.impl = _GetchUnix()

    def __call__(self): return self.impl()


class _GetchUnix:
    def __init__(self):
        import tty, sys, termios # import termios now or else you'll get the Unix version on the Mac

    def __call__(self):
        import sys, tty, termios
        fd = sys.stdin.fileno()
        old_settings = termios.tcgetattr(fd)
        try:
            tty.setraw(sys.stdin.fileno())
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch

class _GetchWindows:
    def __init__(self):
        import msvcrt

    def __call__(self):
        import msvcrt
        return msvcrt.getch()

class _GetchMacCarbon:
    """
    A function which returns the current ASCII key that is down;
    if no ASCII key is down, the null string is returned.  The
    page http://www.mactech.com/macintosh-c/chap02-1.html was
    very helpful in figuring out how to do this.
    """
    def __init__(self):
        import Carbon
        Carbon.Evt #see if it has this (in Unix, it doesn't)

    def __call__(self):
        import Carbon
        if Carbon.Evt.EventAvail(0x0008)[0]==0: # 0x0008 is the keyDownMask
            return ''
        else:
            #
            # The event contains the following info:
            # (what,msg,when,where,mod)=Carbon.Evt.GetNextEvent(0x0008)[1]
            #
            # The message (msg) contains the ASCII char which is
            # extracted with the 0x000000FF charCodeMask; this
            # number is converted to an ASCII character with chr() and
            # returned
            #
            (what,msg,when,where,mod)=Carbon.Evt.GetNextEvent(0x0008)[1]
            return chr(msg & 0x000000FF)

import threading
            
            
# From  https://stackoverflow.com/a/2022629/2924421
class Event(list):
    def __call__(self, *args, **kwargs):
        for f in self:
            f(*args, **kwargs)

    def __repr__(self):
        return "Event(%s)" % list.__repr__(self)            


def getKey():
    inkey = _Getch()
    import sys
    for i in xrange(sys.maxint):
        k=inkey()
        if k<>'':break
    return k

class KeyCallbackFunction():
    callbackParam = None
    actualFunction = None
    
    def __init__(self, actualFunction, callbackParam):
        self.actualFunction = actualFunction
        self.callbackParam = callbackParam

    def doCallback(self, inputKey):
        if not self.actualFunction is None:
            if self.callbackParam is None:
                callbackFunctionThread = threading.Thread(target=self.actualFunction, args=(inputKey,))
            else:
                callbackFunctionThread = threading.Thread(target=self.actualFunction, args=(inputKey,self.callbackParam))
            
            callbackFunctionThread.daemon = True
            callbackFunctionThread.start()
        
        

class KeyCapture():


    gotKeyLock = threading.Lock()
    gotKeys = []
    gotKeyEvent = threading.Event()

    keyBlockingSetKeyLock = threading.Lock()

    addingEventsLock = threading.Lock()
    keyReceiveEvents = Event()


    keysGotLock = threading.Lock()
    keysGot = []

    keyBlockingKeyLockLossy = threading.Lock()
    keyBlockingKeyLossy = None
    keyBlockingEventLossy = threading.Event()
    
    keysBlockingGotLock = threading.Lock()
    keysBlockingGot = []
    keyBlockingGotEvent = threading.Event()
    

    
    wantToStopLock = threading.Lock()
    wantToStop = False
    
    stoppedLock = threading.Lock()
    stopped = True
    
    isRunningEvent = False
    
    getKeyThread = None
    
    keyFunction = None
    keyArgs = None
    
    # Begin capturing keys. A seperate thread is launched that
    # captures key presses, and then these can be received via get,
    # getAsync, and adding an event via addEvent. Note that this
    # will prevent the system to accept keys as normal (say, if
    # you are in a python shell) because it overrides that key
    # capturing behavior.
    
    # If you start capture when it's already been started, a
    # InterruptedError("Keys are still being captured")
    # will be thrown
    
    # Note that get(), getAsync() and events are independent, so if a key is pressed:
    #
    # 1: Any calls to get() that are waiting, with lossy on, will return
    #    that key
    # 2: It will be stored in the queue of get keys, so that get() with lossy
    #    off will return the oldest key pressed not returned by get() yet.
    # 3: All events will be fired with that key as their input
    # 4: It will be stored in the list of getAsync() keys, where that list
    #    will be returned and set to empty list on the next call to getAsync().
    # get() call with it, aand add it to the getAsync() list.
    def startCapture(self, keyFunction=None, args=None):
        # Make sure we aren't already capturing keys
        self.stoppedLock.acquire()
        if not self.stopped:
            self.stoppedLock.release()
            raise InterruptedError("Keys are still being captured")
            return
        self.stopped = False
        self.stoppedLock.release()
        
        # If we have captured before, we need to allow the get() calls to actually
        # wait for key presses now by clearing the event
        if self.keyBlockingEventLossy.is_set():
            self.keyBlockingEventLossy.clear()
            
        # Have one function that we call every time a key is captured, intended for stopping capture
        # as desired
        self.keyFunction = keyFunction
        self.keyArgs = args
        
        # Begin capturing keys (in a seperate thread)
        self.getKeyThread = threading.Thread(target=self._threadProcessKeyPresses)
        self.getKeyThread.daemon = True
        self.getKeyThread.start()
        
        # Process key captures (in a seperate thread)
        self.getKeyThread = threading.Thread(target=self._threadStoreKeyPresses)
        self.getKeyThread.daemon = True
        self.getKeyThread.start()
    
    
    def capturing(self):
        self.stoppedLock.acquire()
        isCapturing = not self.stopped
        self.stoppedLock.release()
        return isCapturing
    # Stops the thread that is capturing keys on the first opporunity
    # has to do so. It usually can't stop immediately because getting a key
    # is a blocking process, so this will probably stop capturing after the
    # next key is pressed.
    #
    # However, Sometimes if you call stopCapture it will stop before starting capturing the
    # next key, due to multithreading race conditions. So if you want to stop capturing
    # reliably, call stopCapture in a function added via addEvent. Then you are
    # guaranteed that capturing will stop immediately after the rest of the callback
    # functions are called (before starting to capture the next key).
    def stopCapture(self):
        self.wantToStopLock.acquire()
        self.wantToStop = True 
        self.wantToStopLock.release()

    # Takes in a function that will be called every time a key is pressed (with that
    # key passed in as the first paramater in that function)
    def addEvent(self, keyPressEventFunction, args=None):   
        self.addingEventsLock.acquire()
        callbackHolder = KeyCallbackFunction(keyPressEventFunction, args)
        self.keyReceiveEvents.append(callbackHolder.doCallback)
        self.addingEventsLock.release()
    def clearEvents(self):
        self.addingEventsLock.acquire()
        self.keyReceiveEvents = Event()
        self.addingEventsLock.release()
    # Gets a key captured by this KeyCapture, blocking until a key is pressed.
    # There is an optional lossy paramater:
    # If True all keys before this call are ignored, and the next pressed key
    #   will be returned.
    # If False this will return the oldest key captured that hasn't
    #   been returned by get yet. False is the default.
    def get(self, lossy=False):
        if lossy:
            # Wait for the next key to be pressed
            self.keyBlockingEventLossy.wait()
            self.keyBlockingKeyLockLossy.acquire()
            keyReceived = self.keyBlockingKeyLossy
            self.keyBlockingKeyLockLossy.release()
            return keyReceived
        else:
            while True:
                # Wait until a key is pressed
                self.keyBlockingGotEvent.wait()
                
                # Get the key pressed
                readKey = None
                self.keysBlockingGotLock.acquire()
                # Get a key if it exists
                if len(self.keysBlockingGot) != 0:
                    readKey = self.keysBlockingGot.pop(0)
                # If we got the last one, tell us to wait
                if len(self.keysBlockingGot) == 0:
                    self.keyBlockingGotEvent.clear()
                self.keysBlockingGotLock.release()
                
                # Process the key (if it actually exists)
                if not readKey is None:
                    return readKey
                
                # Exit if we are stopping
                self.wantToStopLock.acquire()
                if self.wantToStop:
                    self.wantToStopLock.release()
                    return None
                self.wantToStopLock.release()
            
            
            
    
    def clearGetList(self):
        self.keysBlockingGotLock.acquire()
        self.keysBlockingGot = []
        self.keysBlockingGotLock.release()
    
    # Gets a list of all keys pressed since the last call to getAsync, in order
    # from first pressed, second pressed, .., most recent pressed
    def getAsync(self):
        self.keysGotLock.acquire();
        keysPressedList = list(self.keysGot)
        self.keysGot = []
        self.keysGotLock.release()
        return keysPressedList
    
    def clearAsyncList(self):
        self.keysGotLock.acquire();
        self.keysGot = []
        self.keysGotLock.release();

    def _processKey(self, readKey):
        # Append to list for GetKeyAsync
        self.keysGotLock.acquire()
        self.keysGot.append(readKey)
        self.keysGotLock.release()
        
        # Call lossy blocking key events
        self.keyBlockingKeyLockLossy.acquire()
        self.keyBlockingKeyLossy = readKey
        self.keyBlockingEventLossy.set()
        self.keyBlockingEventLossy.clear()
        self.keyBlockingKeyLockLossy.release()
        
        # Call non-lossy blocking key events
        self.keysBlockingGotLock.acquire()
        self.keysBlockingGot.append(readKey)
        if len(self.keysBlockingGot) == 1:
            self.keyBlockingGotEvent.set()
        self.keysBlockingGotLock.release()
        
        # Call events added by AddEvent
        self.addingEventsLock.acquire()
        self.keyReceiveEvents(readKey)
        self.addingEventsLock.release()

    def _threadProcessKeyPresses(self):
        while True:
            # Wait until a key is pressed
            self.gotKeyEvent.wait()
            
            # Get the key pressed
            readKey = None
            self.gotKeyLock.acquire()
            # Get a key if it exists
            if len(self.gotKeys) != 0:
                readKey = self.gotKeys.pop(0)
            # If we got the last one, tell us to wait
            if len(self.gotKeys) == 0:
                self.gotKeyEvent.clear()
            self.gotKeyLock.release()
            
            # Process the key (if it actually exists)
            if not readKey is None:
                self._processKey(readKey)
            
            # Exit if we are stopping
            self.wantToStopLock.acquire()
            if self.wantToStop:
                self.wantToStopLock.release()
                break
            self.wantToStopLock.release()
            
    def _threadStoreKeyPresses(self):
        while True:
            # Get a key
            readKey = getKey()
            
            # Run the potential shut down function
            if not self.keyFunction is None:
                self.keyFunction(readKey, self.keyArgs)
        
            # Add the key to the list of pressed keys
            self.gotKeyLock.acquire()
            self.gotKeys.append(readKey)
            if len(self.gotKeys) == 1:
                self.gotKeyEvent.set()
            self.gotKeyLock.release()
            
            # Exit if we are stopping
            self.wantToStopLock.acquire()
            if self.wantToStop:
                self.wantToStopLock.release()
                self.gotKeyEvent.set()
                break
            self.wantToStopLock.release()
    
        
        # If we have reached here we stopped capturing
        
        # All we need to do to clean up is ensure that
        # all the calls to .get() now return None.
        # To ensure no calls are stuck never returning,
        # we will leave the event set so any tasks waiting
        # for it immediately exit. This will be unset upon
        # starting key capturing again.
        
        self.stoppedLock.acquire()
        
        # We also need to set this to True so we can start up
        # capturing again.
        self.stopped = True
        self.stopped = True
        
        self.keyBlockingKeyLockLossy.acquire()
        self.keyBlockingKeyLossy = None
        self.keyBlockingEventLossy.set()
        self.keyBlockingKeyLockLossy.release()
        
        self.keysBlockingGotLock.acquire()
        self.keyBlockingGotEvent.set()
        self.keysBlockingGotLock.release()
        
        self.stoppedLock.release()

The idea is that you can either simply call keyPress.getKey(), which will read a key from the keyboard, then return it.

If you want something more than that, I made a KeyCapture object. You can create one via something like keys = keyPress.KeyCapture().

Then there are three things you can do:

addEvent(functionName) takes in any function that takes in one parameter. Then every time a key is pressed, this function will be called with that key’s string as it’s input. These are ran in a separate thread, so you can block all you want in them and it won’t mess up the functionality of the KeyCapturer nor delay the other events.

get() returns a key in the same blocking way as before. It is now needed here because the keys are being captured via the KeyCapture object now, so keyPress.getKey() would conflict with that behavior and both of them would miss some keys since only one key can be captured at a time. Also, say the user presses ‘a’, then ‘b’, you call get(), the user presses ‘c’. That get() call will immediately return ‘a’, then if you call it again it will return ‘b’, then ‘c’. If you call it again it will block until another key is pressed. This ensures that you don’t miss any keys, in a blocking way if desired. So in this way it’s a little different than keyPress.getKey() from before

If you want the behavior of getKey() back, get(lossy=True) is like get(), except that it only returns keys pressed after the call to get(). So in the above example, get() would block until the user presses ‘c’, and then if you call it again it will block until another key is pressed.

getAsync() is a little different. It’s designed for something that does a lot of processing, then occasionally comes back and checks which keys were pressed. Thus getAsync() returns a list of all the keys pressed since the last call to getAsync(), in order from oldest key pressed to most recent key pressed. It also doesn’t block, meaning that if no keys have been pressed since the last call to getAsync(), an empty [] will be returned.

To actually start capturing keys, you need to call keys.startCapture() with your keys object made above. startCapture is non-blocking, and simply starts one thread that just records the key presses, and another thread to process those key presses. There are two threads to ensure that the thread that records key presses doesn’t miss any keys.

If you want to stop capturing keys, you can call keys.stopCapture() and it will stop capturing keys. However, since capturing a key is a blocking operation, the thread capturing keys might capture one more key after calling stopCapture().

To prevent this, you can pass in an optional parameter(s) into startCapture(functionName, args) of a function that just does something like checks if a key equals ‘c’ and then exits. It’s important that this function does very little before, for example, a sleep here will cause us to miss keys.

However, if stopCapture() is called in this function, key captures will be stopped immediately, without trying to capture any more, and that all get() calls will be returned immediately, with None if no keys have been pressed yet.

Also, since get() and getAsync() store all the previous keys pressed (until you retrieve them), you can call clearGetList() and clearAsyncList() to forget the keys previously pressed.

Note that get(), getAsync() and events are independent, so if a key is pressed:

  1. One call to get() that is waiting, with lossy on, will return that key. The other waiting calls (if any) will continue waiting.
  2. That key will be stored in the queue of get keys, so that get() with lossy off will return the oldest key pressed not returned by get() yet.
  3. All events will be fired with that key as their input
  4. That key will be stored in the list of getAsync() keys, where that lis twill be returned and set to empty list on the next call to getAsync()

If all this is too much, here is an example use case:

import keyPress
import time
import threading

def KeyPressed(k, printLock):
    printLock.acquire()
    print "Event: " + k
    printLock.release()
    time.sleep(4)
    printLock.acquire()
    print "Event after delay: " + k
    printLock.release()

def GetKeyBlocking(keys, printLock):    
    while keys.capturing():
        keyReceived = keys.get()
        time.sleep(1)
        printLock.acquire()
        if not keyReceived is None:
            print "Block " + keyReceived
        else:
            print "Block None"
        printLock.release()

def GetKeyBlockingLossy(keys, printLock):   
    while keys.capturing():
        keyReceived = keys.get(lossy=True)
        time.sleep(1)
        printLock.acquire()
        if not keyReceived is None:
            print "Lossy: " + keyReceived
        else:
            print "Lossy: None"
        printLock.release()

def CheckToClose(k, (keys, printLock)):
    printLock.acquire()
    print "Close: " + k
    printLock.release()
    if k == "c":
        keys.stopCapture()
        
printLock = threading.Lock()

print "Press a key:"
print "You pressed: " + keyPress.getKey()
print ""

keys = keyPress.KeyCapture()

keys.addEvent(KeyPressed, printLock)



print "Starting capture"
            
keys.startCapture(CheckToClose, (keys, printLock))
            
getKeyBlockingThread = threading.Thread(target=GetKeyBlocking, args=(keys, printLock))
getKeyBlockingThread.daemon = True
getKeyBlockingThread.start()

            
getKeyBlockingThreadLossy = threading.Thread(target=GetKeyBlockingLossy, args=(keys, printLock))
getKeyBlockingThreadLossy.daemon = True
getKeyBlockingThreadLossy.start()

while keys.capturing():
    keysPressed = keys.getAsync()
    printLock.acquire()
    if keysPressed != []:
        print "Async: " + str(keysPressed)
    printLock.release()
    time.sleep(1)

print "done capturing"

It is working well for me from the simple test I made, but I will happily take others feedback as well if there is something I missed.

I posted this here as well.


回答 11

在其他答案之一中,有一个注释提到了cbreak模式,这对于Unix实现很重要,因为您通常不希望^ C(KeyboardError)被getchar占用(就像将终端设置为raw模式时那样),其他答案)。

另一个重要的细节是,如果您要读取一个字符而不是一个字节,则应从输入流中读取4个字节,因为这是单个字符在UTF-8中包含的最大字节数(Python 3+ )。仅读取一个字节会为多字节字符(例如键盘箭头)产生意外结果。

这是我为Unix更改的实现:

import contextlib
import os
import sys
import termios
import tty


_MAX_CHARACTER_BYTE_LENGTH = 4


@contextlib.contextmanager
def _tty_reset(file_descriptor):
    """
    A context manager that saves the tty flags of a file descriptor upon
    entering and restores them upon exiting.
    """
    old_settings = termios.tcgetattr(file_descriptor)
    try:
        yield
    finally:
        termios.tcsetattr(file_descriptor, termios.TCSADRAIN, old_settings)


def get_character(file=sys.stdin):
    """
    Read a single character from the given input stream (defaults to sys.stdin).
    """
    file_descriptor = file.fileno()
    with _tty_reset(file_descriptor):
        tty.setcbreak(file_descriptor)
        return os.read(file_descriptor, _MAX_CHARACTER_BYTE_LENGTH)

A comment in one of the other answers mentioned cbreak mode, which is important for Unix implementations because you generally don’t want ^C (KeyboardError) to be consumed by getchar (as it will when you set the terminal to raw mode, as done by most other answers).

Another important detail is that if you’re looking to read one character and not one byte, you should read 4 bytes from the input stream, as that’s the maximum number of bytes a single character will consist of in UTF-8 (Python 3+). Reading only a single byte will produce unexpected results for multi-byte characters such as keypad arrows.

Here’s my changed implementation for Unix:

import contextlib
import os
import sys
import termios
import tty


_MAX_CHARACTER_BYTE_LENGTH = 4


@contextlib.contextmanager
def _tty_reset(file_descriptor):
    """
    A context manager that saves the tty flags of a file descriptor upon
    entering and restores them upon exiting.
    """
    old_settings = termios.tcgetattr(file_descriptor)
    try:
        yield
    finally:
        termios.tcsetattr(file_descriptor, termios.TCSADRAIN, old_settings)


def get_character(file=sys.stdin):
    """
    Read a single character from the given input stream (defaults to sys.stdin).
    """
    file_descriptor = file.fileno()
    with _tty_reset(file_descriptor):
        tty.setcbreak(file_descriptor)
        return os.read(file_descriptor, _MAX_CHARACTER_BYTE_LENGTH)

回答 12

尝试使用pygame:

import pygame
pygame.init()             // eliminate error, pygame.error: video system not initialized
keys = pygame.key.get_pressed()

if keys[pygame.K_SPACE]:
    d = "space key"

print "You pressed the", d, "."

Try this with pygame:

import pygame
pygame.init()             // eliminate error, pygame.error: video system not initialized
keys = pygame.key.get_pressed()

if keys[pygame.K_SPACE]:
    d = "space key"

print "You pressed the", d, "."

回答 13

ActiveState的配方似乎包含“ posix”系统的一个小错误,可以防止Ctrl-C中断(我使用的是Mac)。如果我在脚本中输入以下代码:

while(True):
    print(getch())

我将永远无法使用来终止脚本Ctrl-C,并且必须杀死终端以逃脱。

我认为以下原因是造成这一点的原因,而且它也太残酷了:

tty.setraw(sys.stdin.fileno())

除此之外,tty实际上并不需要打包,termios足以处理它。

下面是对我有用的改进代码(Ctrl-C将被中断),并具有在getche您键入时回显char 的额外功能:

if sys.platform == 'win32':
    import msvcrt
    getch = msvcrt.getch
    getche = msvcrt.getche
else:
    import sys
    import termios
    def __gen_ch_getter(echo):
        def __fun():
            fd = sys.stdin.fileno()
            oldattr = termios.tcgetattr(fd)
            newattr = oldattr[:]
            try:
                if echo:
                    # disable ctrl character printing, otherwise, backspace will be printed as "^?"
                    lflag = ~(termios.ICANON | termios.ECHOCTL)
                else:
                    lflag = ~(termios.ICANON | termios.ECHO)
                newattr[3] &= lflag
                termios.tcsetattr(fd, termios.TCSADRAIN, newattr)
                ch = sys.stdin.read(1)
                if echo and ord(ch) == 127: # backspace
                    # emulate backspace erasing
                    # https://stackoverflow.com/a/47962872/404271
                    sys.stdout.write('\b \b')
            finally:
                termios.tcsetattr(fd, termios.TCSADRAIN, oldattr)
            return ch
        return __fun
    getch = __gen_ch_getter(False)
    getche = __gen_ch_getter(True)

参考文献:

The ActiveState’s recipe seems to contain a little bug for “posix” systems that prevents Ctrl-C from interrupting (I’m using Mac). If I put the following code in my script:

while(True):
    print(getch())

I will never be able to terminate the script with Ctrl-C, and I have to kill my terminal to escape.

I believe the following line is the cause, and it’s also too brutal:

tty.setraw(sys.stdin.fileno())

Asides from that, package tty is not really needed, termios is enough to handle it.

Below is the improved code that works for me (Ctrl-C will interrupt), with the extra getche function that echo the char as you type:

if sys.platform == 'win32':
    import msvcrt
    getch = msvcrt.getch
    getche = msvcrt.getche
else:
    import sys
    import termios
    def __gen_ch_getter(echo):
        def __fun():
            fd = sys.stdin.fileno()
            oldattr = termios.tcgetattr(fd)
            newattr = oldattr[:]
            try:
                if echo:
                    # disable ctrl character printing, otherwise, backspace will be printed as "^?"
                    lflag = ~(termios.ICANON | termios.ECHOCTL)
                else:
                    lflag = ~(termios.ICANON | termios.ECHO)
                newattr[3] &= lflag
                termios.tcsetattr(fd, termios.TCSADRAIN, newattr)
                ch = sys.stdin.read(1)
                if echo and ord(ch) == 127: # backspace
                    # emulate backspace erasing
                    # https://stackoverflow.com/a/47962872/404271
                    sys.stdout.write('\b \b')
            finally:
                termios.tcsetattr(fd, termios.TCSADRAIN, oldattr)
            return ch
        return __fun
    getch = __gen_ch_getter(False)
    getche = __gen_ch_getter(True)

References:


回答 14

cursespython中的软件包可用于进入“原始”模式,以从终端输入字符而仅需少量语句。Curses的主要用途是接管屏幕进行输出,这可能不是您想要的。该代码段print()改为使用可用的语句,但您必须了解curses如何更改连接到输出的行尾。

#!/usr/bin/python3
# Demo of single char terminal input in raw mode with the curses package.
import sys, curses

def run_one_char(dummy):
    'Run until a carriage return is entered'
    char = ' '
    print('Welcome to curses', flush=True)
    while ord(char) != 13:
        char = one_char()

def one_char():
    'Read one character from the keyboard'
    print('\r? ', flush= True, end = '')

    ## A blocking single char read in raw mode. 
    char = sys.stdin.read(1)
    print('You entered %s\r' % char)
    return char

## Must init curses before calling any functions
curses.initscr()
## To make sure the terminal returns to its initial settings,
## and to set raw mode and guarantee cleanup on exit. 
curses.wrapper(run_one_char)
print('Curses be gone!')

The curses package in python can be used to enter “raw” mode for character input from the terminal with just a few statements. Curses’ main use is to take over the screen for output, which may not be what you want. This code snippet uses print() statements instead, which are usable, but you must be aware of how curses changes line endings attached to output.

#!/usr/bin/python3
# Demo of single char terminal input in raw mode with the curses package.
import sys, curses

def run_one_char(dummy):
    'Run until a carriage return is entered'
    char = ' '
    print('Welcome to curses', flush=True)
    while ord(char) != 13:
        char = one_char()

def one_char():
    'Read one character from the keyboard'
    print('\r? ', flush= True, end = '')

    ## A blocking single char read in raw mode. 
    char = sys.stdin.read(1)
    print('You entered %s\r' % char)
    return char

## Must init curses before calling any functions
curses.initscr()
## To make sure the terminal returns to its initial settings,
## and to set raw mode and guarantee cleanup on exit. 
curses.wrapper(run_one_char)
print('Curses be gone!')

回答 15

如果我正在做复杂的事情,我将使用诅咒来读取键。但是很多时候我只想要一个简单的Python 3脚本,该脚本使用标准库并且可以读取箭头键,所以我这样做:

import sys, termios, tty

key_Enter = 13
key_Esc = 27
key_Up = '\033[A'
key_Dn = '\033[B'
key_Rt = '\033[C'
key_Lt = '\033[D'

fdInput = sys.stdin.fileno()
termAttr = termios.tcgetattr(0)

def getch():
    tty.setraw(fdInput)
    ch = sys.stdin.buffer.raw.read(4).decode(sys.stdin.encoding)
    if len(ch) == 1:
        if ord(ch) < 32 or ord(ch) > 126:
            ch = ord(ch)
    elif ord(ch[0]) == 27:
        ch = '\033' + ch[1:]
    termios.tcsetattr(fdInput, termios.TCSADRAIN, termAttr)
    return ch

If I’m doing something complicated I’ll use curses to read keys. But a lot of times I just want a simple Python 3 script that uses the standard library and can read arrow keys, so I do this:

import sys, termios, tty

key_Enter = 13
key_Esc = 27
key_Up = '\033[A'
key_Dn = '\033[B'
key_Rt = '\033[C'
key_Lt = '\033[D'

fdInput = sys.stdin.fileno()
termAttr = termios.tcgetattr(0)

def getch():
    tty.setraw(fdInput)
    ch = sys.stdin.buffer.raw.read(4).decode(sys.stdin.encoding)
    if len(ch) == 1:
        if ord(ch) < 32 or ord(ch) > 126:
            ch = ord(ch)
    elif ord(ch[0]) == 27:
        ch = '\033' + ch[1:]
    termios.tcsetattr(fdInput, termios.TCSADRAIN, termAttr)
    return ch

回答 16

我对python3的解决方案,不依赖于任何pip包。

# precondition: import tty, sys
def query_yes_no(question, default=True):
    """
    Ask the user a yes/no question.
    Returns immediately upon reading one-char answer.
    Accepts multiple language characters for yes/no.
    """
    if not sys.stdin.isatty():
        return default
    if default:
        prompt = "[Y/n]?"
        other_answers = "n"
    else:
        prompt = "[y/N]?"
        other_answers = "yjosiá"

    print(question,prompt,flush= True,end=" ")
    oldttysettings = tty.tcgetattr(sys.stdin.fileno())
    try:
        tty.setraw(sys.stdin.fileno())
        return not sys.stdin.read(1).lower() in other_answers
    except:
        return default
    finally:
        tty.tcsetattr(sys.stdin.fileno(), tty.TCSADRAIN , oldttysettings)
        sys.stdout.write("\r\n")
        tty.tcdrain(sys.stdin.fileno())

My solution for python3, not depending on any pip packages.

# precondition: import tty, sys
def query_yes_no(question, default=True):
    """
    Ask the user a yes/no question.
    Returns immediately upon reading one-char answer.
    Accepts multiple language characters for yes/no.
    """
    if not sys.stdin.isatty():
        return default
    if default:
        prompt = "[Y/n]?"
        other_answers = "n"
    else:
        prompt = "[y/N]?"
        other_answers = "yjosiá"

    print(question,prompt,flush= True,end=" ")
    oldttysettings = tty.tcgetattr(sys.stdin.fileno())
    try:
        tty.setraw(sys.stdin.fileno())
        return not sys.stdin.read(1).lower() in other_answers
    except:
        return default
    finally:
        tty.tcsetattr(sys.stdin.fileno(), tty.TCSADRAIN , oldttysettings)
        sys.stdout.write("\r\n")
        tty.tcdrain(sys.stdin.fileno())

回答 17

我相信这是最优雅的解决方案之一。

import os

if os.name == 'nt':
    import msvcrt
    def getch():
        return msvcrt.getch().decode()
else:
    import sys, tty, termios
    fd = sys.stdin.fileno()
    old_settings = termios.tcgetattr(fd)
    def getch():
        try:
            tty.setraw(sys.stdin.fileno())
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch

然后在代码中使用它:

if getch() == chr(ESC_ASCII_VALUE):
    print("ESC!")

I believe that this is one the most elegant solution.

import os

if os.name == 'nt':
    import msvcrt
    def getch():
        return msvcrt.getch().decode()
else:
    import sys, tty, termios
    fd = sys.stdin.fileno()
    old_settings = termios.tcgetattr(fd)
    def getch():
        try:
            tty.setraw(sys.stdin.fileno())
            ch = sys.stdin.read(1)
        finally:
            termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
        return ch

and then use it in the code:

if getch() == chr(ESC_ASCII_VALUE):
    print("ESC!")

回答 18

接受的答案对我而言效果不佳(我按住一个键,什么也不会发生,然后按另一个键便可以使用)。

在了解了curses模块之后,确实看起来是正确的方法。现在它可以通过Windows光标(可通过pip获得)用于Windows ,因此您可以以与平台无关的方式进行编程。这是一个受YouTube上不错的教程启发的示例:

import curses                                                                                                                                       
def getkey(stdscr):
    curses.curs_set(0)
    while True:
        key = stdscr.getch()
        if key != -1:
            break
    return key

if __name__ == "__main__":
    print(curses.wrapper(getkey))

使用.py扩展名保存它,或curses.wrapper(getkey)在交互模式下运行。

The accepted answer didn’t perform that well for me (I’d hold a key, nothing would happen, then I’d press another key and it would work).

After learning about the curses module, it really seems like the right way to go. And it’s now available for Windows through windows-cursors (available through pip), so you can program in a platform agnostic manner. Here’s an example inspired by this nice tutorial on YouTube:

import curses                                                                                                                                       
def getkey(stdscr):
    curses.curs_set(0)
    while True:
        key = stdscr.getch()
        if key != -1:
            break
    return key

if __name__ == "__main__":
    print(curses.wrapper(getkey))

Save it with a .py extension, or run curses.wrapper(getkey) in interactive mode.


回答 19

在这里回答:python中的raw_input,而无需按Enter

使用此代码-

from tkinter import Tk, Frame


def __set_key(e, root):
    """
    e - event with attribute 'char', the released key
    """
    global key_pressed
    if e.char:
        key_pressed = e.char
        root.destroy()


def get_key(msg="Press any key ...", time_to_sleep=3):
    """
    msg - set to empty string if you don't want to print anything
    time_to_sleep - default 3 seconds
    """
    global key_pressed
    if msg:
        print(msg)
    key_pressed = None
    root = Tk()
    root.overrideredirect(True)
    frame = Frame(root, width=0, height=0)
    frame.bind("<KeyRelease>", lambda f: __set_key(f, root))
    frame.pack()
    root.focus_set()
    frame.focus_set()
    frame.focus_force()  # doesn't work in a while loop without it
    root.after(time_to_sleep * 1000, func=root.destroy)
    root.mainloop()
    root = None  # just in case
    return key_pressed


def __main():
        c = None
        while not c:
                c = get_key("Choose your weapon ... ", 2)
        print(c)

if __name__ == "__main__":
    __main()

参考:https : //github.com/unfor19/mg-tools/blob/master/mgtools/get_key_pressed.py

Answered here: raw_input in python without pressing enter

Use this code-

from tkinter import Tk, Frame


def __set_key(e, root):
    """
    e - event with attribute 'char', the released key
    """
    global key_pressed
    if e.char:
        key_pressed = e.char
        root.destroy()


def get_key(msg="Press any key ...", time_to_sleep=3):
    """
    msg - set to empty string if you don't want to print anything
    time_to_sleep - default 3 seconds
    """
    global key_pressed
    if msg:
        print(msg)
    key_pressed = None
    root = Tk()
    root.overrideredirect(True)
    frame = Frame(root, width=0, height=0)
    frame.bind("<KeyRelease>", lambda f: __set_key(f, root))
    frame.pack()
    root.focus_set()
    frame.focus_set()
    frame.focus_force()  # doesn't work in a while loop without it
    root.after(time_to_sleep * 1000, func=root.destroy)
    root.mainloop()
    root = None  # just in case
    return key_pressed


def __main():
        c = None
        while not c:
                c = get_key("Choose your weapon ... ", 2)
        print(c)

if __name__ == "__main__":
    __main()

Reference: https://github.com/unfor19/mg-tools/blob/master/mgtools/get_key_pressed.py


回答 20

如果您只想注册一个按键,即使用户多次按下该按键或保持按键按下时间更长。为避免获得多个按下的输入,请使用while循环并将其传递。

import keyboard

while(True):
  if(keyboard.is_pressed('w')):
      s+=1
      while(keyboard.is_pressed('w')):
        pass
  if(keyboard.is_pressed('s')):
      s-=1
      while(keyboard.is_pressed('s')):
        pass
  print(s)

If you want to register only one single key press even if the user pressed it for more than once or kept pressing the key longer. To avoid getting multiple pressed inputs use the while loop and pass it.

import keyboard

while(True):
  if(keyboard.is_pressed('w')):
      s+=1
      while(keyboard.is_pressed('w')):
        pass
  if(keyboard.is_pressed('s')):
      s-=1
      while(keyboard.is_pressed('s')):
        pass
  print(s)

回答 21

如果您只想按住屏幕,以便可以在终端上看到结果,只需编写

input()

在代码末尾,它将保留屏幕

if you just want to hold the screen so you can see the result on the terminal just write

input()

at the end of the code and it will hold the screen


回答 22

内置的raw_input应该会有所帮助。

for i in range(3):
    print ("So much work to do!")
k = raw_input("Press any key to continue...")
print ("Ok, back to work.")

The build-in raw_input should help.

for i in range(3):
    print ("So much work to do!")
k = raw_input("Press any key to continue...")
print ("Ok, back to work.")