问题:如何在Python中更改工作目录?
cd
是用于更改工作目录的shell命令。
如何在Python中更改当前的工作目录?
回答 0
您可以使用以下命令更改工作目录:
import os
os.chdir(path)
使用此方法时,有两个最佳实践:
- 在无效路径上捕获异常(WindowsError,OSError)。如果抛出异常,请不要执行任何递归操作,尤其是破坏性操作。它们将沿旧路径而不是新路径运行。
- 完成后,返回到旧目录。可以通过将chdir调用包装在上下文管理器中以异常安全的方式完成,就像Brian M. Hunt在他的答案中所做的那样。
更改子流程中的当前工作目录不会更改父流程中的当前工作目录。Python解释器也是如此。您不能用于os.chdir()
更改呼叫过程的CWD。
回答 1
这是上下文管理器更改工作目录的示例。它比其他地方提到的ActiveState版本要简单,但这可以完成工作。
上下文管理器: cd
import os
class cd:
"""Context manager for changing the current working directory"""
def __init__(self, newPath):
self.newPath = os.path.expanduser(newPath)
def __enter__(self):
self.savedPath = os.getcwd()
os.chdir(self.newPath)
def __exit__(self, etype, value, traceback):
os.chdir(self.savedPath)
或者使用ContextManager尝试更简洁的等效方法(如下)。
例
import subprocess # just to call an arbitrary command e.g. 'ls'
# enter the directory like this:
with cd("~/Library"):
# we are in ~/Library
subprocess.call("ls")
# outside the context manager we are back wherever we started.
回答 2
回答 3
cd()
使用生成器和装饰器很容易编写。
from contextlib import contextmanager
import os
@contextmanager
def cd(newdir):
prevdir = os.getcwd()
os.chdir(os.path.expanduser(newdir))
try:
yield
finally:
os.chdir(prevdir)
然后,即使在引发异常之后,也将还原目录:
os.chdir('/home')
with cd('/tmp'):
# ...
raise Exception("There's no place like home.")
# Directory is now back to '/home'.
回答 4
如果您使用的Python的一个相对较新的版本,你也可以使用一个上下文管理器,比如这一个:
from __future__ import with_statement
from grizzled.os import working_directory
with working_directory(path_to_directory):
# code in here occurs within the directory
# code here is in the original directory
更新
如果您喜欢自己动手:
import os
from contextlib import contextmanager
@contextmanager
def working_directory(directory):
owd = os.getcwd()
try:
os.chdir(directory)
yield directory
finally:
os.chdir(owd)
回答 5
正如其他人已经指出的那样,以上所有解决方案仅会更改当前进程的工作目录。当您返回Unix shell时,这将丢失。如果不顾一切,您可以使用以下可怕的方法在Unix上更改父shell目录:
def quote_against_shell_expansion(s):
import pipes
return pipes.quote(s)
def put_text_back_into_terminal_input_buffer(text):
# use of this means that it only works in an interactive session
# (and if the user types while it runs they could insert characters between the characters in 'text'!)
import fcntl, termios
for c in text:
fcntl.ioctl(1, termios.TIOCSTI, c)
def change_parent_process_directory(dest):
# the horror
put_text_back_into_terminal_input_buffer("cd "+quote_against_shell_expansion(dest)+"\n")
回答 6
os.chdir()
是正确的方法。
回答 7
os.chdir()
是的Python版本cd
。
回答 8
import os
abs_path = 'C://a/b/c'
rel_path = './folder'
os.chdir(abs_path)
os.chdir(rel_path)
您可以同时使用os.chdir(abs_path)或os.chdir(rel_path),无需调用os.getcwd()即可使用相对路径。
回答 9
进一步进入方向指出了由Brian和基于SH(1.0.8+)
from sh import cd, ls
cd('/tmp')
print ls()
回答 10
如果您想执行“ cd ..”选项,只需键入:
os.chdir(“ ..”)
它与Windows cmd中的相同:cd。。当然,导入os是必需的(例如,将其键入为代码的第一行)。
回答 11
如果您使用spyder和love GUI,则只需单击屏幕右上角的文件夹按钮,然后浏览要用作当前目录的文件夹/目录。完成此操作后,您可以转到spyder IDE中窗口的文件浏览器选项卡,然后可以看到其中存在的所有文件/文件夹。要检查当前工作目录,请转到spyder IDE的控制台,然后键入
pwd
它将打印与之前选择的路径相同的路径。
回答 12
更改脚本过程的当前目录很简单。我认为问题实际上是如何更改从中调用python脚本的命令窗口的当前目录,这非常困难。Windows中的Bat脚本或Bash shell中的Bash脚本可以使用普通的cd命令来执行此操作,因为shell本身就是解释器。在Windows和Linux中,Python都是程序,任何程序都不能直接更改其父级的环境。但是,将简单的Shell脚本与Python脚本结合使用可完成大多数艰苦的工作,即可达到预期的效果。例如,为了制作具有遍历历史记录的扩展cd命令以进行向后/向前/选择重新访问,我编写了一个相对复杂的Python脚本,该脚本由一个简单的bat脚本调用。遍历列表存储在文件中,目标目录位于第一行。当python脚本返回时,bat脚本读取文件的第一行并将其作为cd的参数。完整的蝙蝠脚本(为简洁起见,减去注释)为:
if _%1 == _. goto cdDone
if _%1 == _? goto help
if /i _%1 NEQ _-H goto doCd
:help
echo d.bat and dSup.py 2016.03.05. Extended chdir.
echo -C = clear traversal list.
echo -B or nothing = backward (to previous dir).
echo -F or - = forward (to next dir).
echo -R = remove current from list and return to previous.
echo -S = select from list.
echo -H, -h, ? = help.
echo . = make window title current directory.
echo Anything else = target directory.
goto done
:doCd
%~dp0dSup.py %1
for /F %%d in ( %~dp0dSupList ) do (
cd %%d
if errorlevel 1 ( %~dp0dSup.py -R )
goto cdDone
)
:cdDone
title %CD%
:done
python脚本dSup.py是:
import sys, os, msvcrt
def indexNoCase ( slist, s ) :
for idx in range( len( slist )) :
if slist[idx].upper() == s.upper() :
return idx
raise ValueError
# .........main process ...................
if len( sys.argv ) < 2 :
cmd = 1 # No argument defaults to -B, the most common operation
elif sys.argv[1][0] == '-':
if len(sys.argv[1]) == 1 :
cmd = 2 # '-' alone defaults to -F, second most common operation.
else :
cmd = 'CBFRS'.find( sys.argv[1][1:2].upper())
else :
cmd = -1
dir = os.path.abspath( sys.argv[1] ) + '\n'
# cmd is -1 = path, 0 = C, 1 = B, 2 = F, 3 = R, 4 = S
fo = open( os.path.dirname( sys.argv[0] ) + '\\dSupList', mode = 'a+t' )
fo.seek( 0 )
dlist = fo.readlines( -1 )
if len( dlist ) == 0 :
dlist.append( os.getcwd() + '\n' ) # Prime new directory list with current.
if cmd == 1 : # B: move backward, i.e. to previous
target = dlist.pop(0)
dlist.append( target )
elif cmd == 2 : # F: move forward, i.e. to next
target = dlist.pop( len( dlist ) - 1 )
dlist.insert( 0, target )
elif cmd == 3 : # R: remove current from list. This forces cd to previous, a
# desireable side-effect
dlist.pop( 0 )
elif cmd == 4 : # S: select from list
# The current directory (dlist[0]) is included essentially as ESC.
for idx in range( len( dlist )) :
print( '(' + str( idx ) + ')', dlist[ idx ][:-1])
while True :
inp = msvcrt.getche()
if inp.isdigit() :
inp = int( inp )
if inp < len( dlist ) :
print( '' ) # Print the newline we didn't get from getche.
break
print( ' is out of range' )
# Select 0 means the current directory and the list is not changed. Otherwise
# the selected directory is moved to the top of the list. This can be done by
# either rotating the whole list until the selection is at the head or pop it
# and insert it to 0. It isn't obvious which would be better for the user but
# since pop-insert is simpler, it is used.
if inp > 0 :
dlist.insert( 0, dlist.pop( inp ))
elif cmd == -1 : # -1: dir is the requested new directory.
# If it is already in the list then remove it before inserting it at the head.
# This takes care of both the common case of it having been recently visited
# and the less common case of user mistakenly requesting current, in which
# case it is already at the head. Deleting and putting it back is a trivial
# inefficiency.
try:
dlist.pop( indexNoCase( dlist, dir ))
except ValueError :
pass
dlist = dlist[:9] # Control list length by removing older dirs (should be
# no more than one).
dlist.insert( 0, dir )
fo.truncate( 0 )
if cmd != 0 : # C: clear the list
fo.writelines( dlist )
fo.close()
exit(0)