


An introduction to the understanding of RawString in Python
总结
1、'''作用: 可以表示 "多行注释" 、"多行字符串" 、"其内的单双引号不转义"
2、r 代表的意思是: raw
3、r 只对其内的反斜杠起作用(注意单个 \ 的问题)
raw string 有什么用处呢? raw string 就是会自动将反斜杠转义。
>>> print('\n') >>> print(r'\n') \n >>>
(注:出现了两个空行是因为 print() 会自动添加一个空行)
再举个例子:
>>> r'\\\\\\' == '\\\\\\\\\\\\' True >>> print('\\\\\\\\\\\\') \\\\\\ >>> print(r'\\\\\\') \\\\\\ >>>
上述就是raw string 的基本功能。
所谓的
print(r'''1 2 3 4''')
和
print('''1 2 3 4''')
效果一样的原因其实就在于
三引号内没有 \ 所以 r 英雄无用武之地
有一点要注意的是,raw string 并不能让诸如 print(r'\') 起作用。因为在编译时Python还是会尝试使用反斜杠来转义单引号,从而造成字符串没有终止的问题.
举例:
>>> print(r'C:\Windows\System32')
C:\Windows\System32
>>> print('C:\\Windows\\System32') C:\Windows\System32 >>> print('C:\Windows\System32') C:\Windows\System32 >>>
最后一行也可以生效的原因是,\W 和 \S 什么都不是。所以在这个例子中Python发现“无法转义”,所以就不做任何转义而直接打印转义符。但是:
>>> print('C:\Windows\System32\new') C:\Windows\System32 ew >>> print(r'C:\Windows\System32\new') C:\Windows\System32\new
就不一样了。
以上这篇对于Python中RawString的理解介绍就是小编分享给大家的全部内容了,希望能给大家一个参考,也希望大家多多支持脚本之家。

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