Python字符串转义的十六进制 [英] Python String to Escaped Hex

问题描述

下面有一些python代码，我设法拼凑起来以实现所需的功能，但是对于python来说，它是一个新手，我认为应该有一个比这里的解决方案优雅得多的解决方案.

I have some python code below I managed to cobble together to achieve what I needed, but being quite new to python I believe there should be a much more elegant solution than the one I have here.

基本上，我需要获取一个任意字符串(MAGICSTRING)并将其每个字符转换为它们的十六进制值，然后将0x00填充到结果十六进制字符串的开头和结尾，最后将末尾整个填充字符串的长度.然后，我需要这些转义符，以便以后可以将其传递给套接字连接.

Essentially I need to take an arbitrary string (MAGICSTRING) and convert each of it's characters into their hex value, then pad a 0x00 to the start and end of the resultant hex string, and finally put the hex value of the length of the entire padded string on the end. I then need these escaped so it can be passed to a socket connection later on.

在示例中，MAGICSTRING为1234，并且'value'的预期结果为'\x00\x31\x32\x33\x34\x00\x06'

In the example, MAGICSTRING is 1234, and the expected result of 'value' is '\x00\x31\x32\x33\x34\x00\x06'

请参见下面的示例.

MAGICSTRING = '1234'
i=0
hexpass = ''
while i < len(MAGICSTRING):
    hexpass = hexpass + hex(ord(MAGICSTRING[i]))[2:]
    i += 1
strlen = len(MAGICSTRING) + 2
sendstr = '00'+ hexpass + '00' + '0' + hex(strlen)[2:]
value = sendstr.decode('hex')

赞赏可以对上述内容进行的任何改进.

Appreciate any improvements that can be made to the above.

推荐答案

字符串'1234'已已经等效于'\x31\x32\x33\x34':

>>> '\x31\x32\x33\x34'
'1234'
>>> '\x31\x32\x33\x34' == '1234'
True

因此将其编码为十六进制然后再次解码是..繁忙的工作:

thus encoding that to hex then decoding it again is.. busy work:

>>> '1234'.encode('hex').decode('hex')
'1234'

\xhh只是一个标记，可以帮助您创建值.当回显字节字符串时，Python始终将直接显示可打印的ASCII字符，而不是使用\xhh表示法.

\xhh is just a notation to help you create the values; when echoing a byte string Python will always display printable ASCII characters directly rather than use the \xhh notation.

此处的十六进制表示法只是表达每个字节的值的一种方法，它实际上是0到255之间的整数.Python字符串中的每个字节都是具有这样约束值的字节，并编码为编解码器会为这些字节生成一个带有十六进制数字的字符串，并再次从十六进制数字生成字节.

Hex notation here is just a way to express the values of each byte, which is really an integer between 0 and 255. Each byte in a Python string is then a byte with such a constrained value, and encoding to the 'hex' codec produces a string with hex digits for those bytes, and bytes again from the hex digits.

因此，您要做的就是添加\x00空字节和长度:

As such, all you have to do is add the \x00 null bytes and the length:

MAGICSTRING = '1234'
value = '\x00{}\x00{}'.format(MAGICSTRING, chr(len(MAGICSTRING) + 2))

此处，\xhh表示法用于产生空字节，而 chr()函数产生长度字节".

Here the \xhh notation is used to produce the null bytes, and the chr() function produces the length 'byte'.

演示:

>>> MAGICSTRING = '1234'
>>> '\x00{}\x00{}'.format(MAGICSTRING, chr(len(MAGICSTRING) + 2))
'\x001234\x00\x06'
>>> '\x00{}\x00{}'.format(MAGICSTRING, chr(len(MAGICSTRING) + 2)) == '\x00\x31\x32\x33\x34\x00\x06'
True

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