问题:在Python中将十六进制字符串转换为int

如何在Python中将十六进制字符串转换为int?

我可能将其命名为“ 0xffff”或“ ffff”。

How do I convert a hex string to an int in Python?

I may have it as “0xffff” or just “ffff“.


回答 0

如果没有 0x前缀,则需要显式指定基数,否则无法告诉:

x = int("deadbeef", 16)

使用 0x前缀,Python可以自动区分十六进制和十进制。

>>> print int("0xdeadbeef", 0)
3735928559
>>> print int("10", 0)
10

(您必须指定0作为基准才能调用此前缀猜测行为;省略第二个参数意味着假定基准为10。)

Without the 0x prefix, you need to specify the base explicitly, otherwise there’s no way to tell:

x = int("deadbeef", 16)

With the 0x prefix, Python can distinguish hex and decimal automatically.

>>> print int("0xdeadbeef", 0)
3735928559
>>> print int("10", 0)
10

(You must specify 0 as the base in order to invoke this prefix-guessing behavior; omitting the second parameter means to assume base-10.)


回答 1

int(hexString, 16) 可以解决问题,并且可以使用和不使用0x前缀:

>>> int("a", 16)
10
>>> int("0xa",16)
10

int(hexString, 16) does the trick, and works with and without the 0x prefix:

>>> int("a", 16)
10
>>> int("0xa",16)
10

回答 2

对于任何给定的字符串s:

int(s, 16)

For any given string s:

int(s, 16)

回答 3

在Python中将十六进制字符串转换为int

我可能有它"0xffff"或只是它"ffff"

要将字符串转换为int,请将字符串int与要转换的基数一起传递给。

两个字符串都可以通过以下方式进行转换:

>>> string_1 = "0xffff"
>>> string_2 = "ffff"
>>> int(string_1, 16)
65535
>>> int(string_2, 16)
65535

int推断

如果您将0作为基数,int则将从字符串中的前缀推断基数。

>>> int(string_1, 0)
65535

如果没有十六进制前缀0xint没有足够的信息与猜测:

>>> int(string_2, 0)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid literal for int() with base 0: 'ffff'

文字:

如果您要输入源代码或解释器,Python将为您进行转换:

>>> integer = 0xffff
>>> integer
65535

这将无法使用,ffff因为Python会认为您正在尝试编写合法的Python名称:

>>> integer = ffff
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'ffff' is not defined

Python数字以数字字符开头,而Python名称不能以数字字符开头。

Convert hex string to int in Python

I may have it as "0xffff" or just "ffff".

To convert a string to an int, pass the string to int along with the base you are converting from.

Both strings will suffice for conversion in this way:

>>> string_1 = "0xffff"
>>> string_2 = "ffff"
>>> int(string_1, 16)
65535
>>> int(string_2, 16)
65535

Letting int infer

If you pass 0 as the base, int will infer the base from the prefix in the string.

>>> int(string_1, 0)
65535

Without the hexadecimal prefix, 0x, int does not have enough information with which to guess:

>>> int(string_2, 0)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid literal for int() with base 0: 'ffff'

literals:

If you’re typing into source code or an interpreter, Python will make the conversion for you:

>>> integer = 0xffff
>>> integer
65535

This won’t work with ffff because Python will think you’re trying to write a legitimate Python name instead:

>>> integer = ffff
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'ffff' is not defined

Python numbers start with a numeric character, while Python names cannot start with a numeric character.


回答 4

在上述Dan的答案中加上:如果为int()函数提供了十六进制字符串,则必须将基数指定为16,否则它不会认为您给了它有效的值。对于字符串中不包含的十六进制数字,无需指定基数16。

print int(0xdeadbeef) # valid

myHex = "0xdeadbeef"
print int(myHex) # invalid, raises ValueError
print int(myHex , 16) # valid

Adding to Dan’s answer above: if you supply the int() function with a hex string, you will have to specify the base as 16 or it will not think you gave it a valid value. Specifying base 16 is unnecessary for hex numbers not contained in strings.

print int(0xdeadbeef) # valid

myHex = "0xdeadbeef"
print int(myHex) # invalid, raises ValueError
print int(myHex , 16) # valid

回答 5

最坏的方法:

>>> def hex_to_int(x):
    return eval("0x" + x)

>>> hex_to_int("c0ffee")
12648430

请不要这样做!

在Python中使用eval是不好的做法吗?

The worst way:

>>> def hex_to_int(x):
    return eval("0x" + x)

>>> hex_to_int("c0ffee")
12648430

Please don’t do this!

Is using eval in Python a bad practice?


回答 6

或者ast.literal_eval(这很安全,不像eval):

ast.literal_eval("0xffff")

演示:

>>> import ast
>>> ast.literal_eval("0xffff")
65535
>>> 

Or ast.literal_eval (this is safe, unlike eval):

ast.literal_eval("0xffff")

Demo:

>>> import ast
>>> ast.literal_eval("0xffff")
65535
>>> 

回答 7

格式化程序选项’%x’%对我来说似乎也可以在赋值语句中使用。(假设Python 3.0及更高版本)

a = int('0x100', 16)
print(a)   #256
print('%x' % a) #100
b = a
print(b) #256
c = '%x' % a
print(c) #100

The formatter option ‘%x’ % seems to work in assignment statements as well for me. (Assuming Python 3.0 and later)

Example

a = int('0x100', 16)
print(a)   #256
print('%x' % a) #100
b = a
print(b) #256
c = '%x' % a
print(c) #100

回答 8

如果您使用的是python解释器,则只需键入0x(您的十六进制值),解释器就会自动为您转换。

>>> 0xffff

65535

If you are using the python interpreter, you can just type 0x(your hex value) and the interpreter will convert it automatically for you.

>>> 0xffff

65535

回答 9

处理十六进制,八进制,二进制,整数和浮点数

使用标准前缀(即0x,0b,0和0o),此函数会将任何合适的字符串转换为数字。我在这里回答了这个问题:https : //stackoverflow.com/a/58997070/2464381,但这是必需的功能。

def to_number(n):
    ''' Convert any number representation to a number 
    This covers: float, decimal, hex, and octal numbers.
    '''

    try:
        return int(str(n), 0)
    except:
        try:
            # python 3 doesn't accept "010" as a valid octal.  You must use the
            # '0o' prefix
            return int('0o' + n, 0)
        except:
            return float(n)

Handles hex, octal, binary, int, and float

Using the standard prefixes (i.e. 0x, 0b, 0, and 0o) this function will convert any suitable string to a number. I answered this here: https://stackoverflow.com/a/58997070/2464381 but here is the needed function.

def to_number(n):
    ''' Convert any number representation to a number 
    This covers: float, decimal, hex, and octal numbers.
    '''

    try:
        return int(str(n), 0)
    except:
        try:
            # python 3 doesn't accept "010" as a valid octal.  You must use the
            # '0o' prefix
            return int('0o' + n, 0)
        except:
            return float(n)

回答 10

在Python 2.7中,int('deadbeef',10)似乎不起作用。

以下对我有用:

>>a = int('deadbeef',16)
>>float(a)
3735928559.0

In Python 2.7, int('deadbeef',10) doesn’t seem to work.

The following works for me:

>>a = int('deadbeef',16)
>>float(a)
3735928559.0

回答 11

加上“ 0x”前缀,您也可以使用eval函数

例如

>>a='0xff'
>>eval(a)
255

with ‘0x’ prefix, you might also use eval function

For example

>>a='0xff'
>>eval(a)
255

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