python - 如何转义Python中所有未转义的斜杠

Question

我在Python中有一个部分转义的路径，如下所示:

path = "C:\\Temp\\\\TestEmpty" # Actual value = C:\Temp\\TestEmpty

我想让所有斜杠都像这样加倍:

escapedpath = "C:\\\\Temp\\\\TestEmpty" # Actual value = C:\\Temp\\TestEmpty

我从一些正则表达式开始

escapedpath = re.sub("[a-zA-Z0-9 _:-](\\)[a-zA-Z0-9 _:-]", "\\\\", path)

...但是这当然会删除 \\s

之前和之后的字符

这是怎么做到的？

Answer 1

result = re.sub(r"""(?x)
    (?<!\\)     # Make sure that there is no backslash before the current position
    \\          # Match a backslash
    (?=         # only if...
     (?:\\\\)*  # an even number of backslashes follows (including zero)
     (?!\\)     # and no further backslashes follow after that
    )           # (End of lookahead assertion)""", 
    r"\\\\", subject)

仅当此时连续反斜杠的数量为奇数时才替换反斜杠。