python中字符串的反斜杠问题

女爷i 2022-05-29 13:43 226阅读 0赞

1,当反斜杠中不含转义字符时可以依旧打印,结果不变,但不鼓励

>>> mystr='C:\Program Files\python\Good'
    >>> mystr
    'C:\\Program Files\\python\\Good'
    >>> print(mystr)
    C:\Program Files\python\Good

2,当反斜杠和其之后的字符组合成转义字符时,输出结果会发生改变

>>> mystr='C:\numpyPacket\Program Files\python\Good'
    >>> mystr
    'C:\numpyPacket\\Program Files\\python\\Good'
    >>> print(mystr)
    C:
    umpyPacket\Program Files\python\Good

3.上述情况的解决方案一是在输出所有反斜杠处的位置,使用转义字符\\,再输出其自身.二是使用原始字符串r,即在字符串之前加个小r

mystr='C:\\numpyPacket\\Program Files\\python\\Good'
    >>> mystr
    'C:\\numpyPacket\\Program Files\\python\\Good'
    >>> print(mystr)
    C:\numpyPacket\Program Files\python\Good

>>> mystr=r'C:\numpyPacket\Program Files\python\Good'
    >>> mystr
    'C:\\numpyPacket\\Program Files\\python\\Good'
    >>> print(mystr)
    C:\numpyPacket\Program Files\python\Good

4,如果要在字符串末尾连接反斜杠或双反斜杠,该如何操作

首先,直接在字符串末尾加反斜杠或使用转义字符添加双反斜杠都不可行

mystr='C:\numpyPacket\Program Files\python\Good\'
    SyntaxError: EOL while scanning string literal

mystr='C:\\numpyPacket\\Program Files\\python\\Good\\\'
    SyntaxError: EOL while scanning string literal

>>> mystr=r'C:\numpyPacket\Program Files\python\Good\'
    SyntaxError: EOL while scanning string literal
    >>>

正确的操作:

字符串末尾只有一个斜杠:

>>> mystr='C:\\numpyPacket\\Program Files\\python\\Good\\'
    >>> mystr
    'C:\\numpyPacket\\Program Files\\python\\Good\\'
    >>> print(mystr)
    C:\numpyPacket\Program Files\python\Good\

字符串末尾有2个斜杠:

>>> mystr='C:\\numpyPacket\\Program Files\\python\\Good\\\\'
    >>> mystr
    'C:\\numpyPacket\\Program Files\\python\\Good\\\\'
    >>> print(mystr)
    C:\numpyPacket\Program Files\python\Good\\

>>> mystr=r'C:\numpyPacket\Program Files\python\Good\\'
    >>> mystr
    'C:\\numpyPacket\\Program Files\\python\\Good\\\\'
    >>> print(mystr)
    C:\numpyPacket\Program Files\python\Good\\