Question

content = 'abcdd'


import re,os,sys
def test():
    print content
    list = re.findall(r'[.\n]+',content)
    print list

if __name__ == '__main__':
    test()

I know ‘.’ represent any charaters except ‘\n’

so [.\n] should represent any characters

but the result is []

why

can you help me ?

thank you in avdanvce !

Answer 1

. inside character class [] loses its special meaning of “all characters (except newline or not depending on flag)” and is only a plain full stop ..

So [.\n] only matches full stop . or new line character.

If you want to match any character (without exception), one trick is to form a character class of complementing character classes, e.g. [\s\S]. This is useful when the regular expression of the language doesn’t support DOTALL option, which makes . matches any character.

However, since Python supports DOTALL option (re.DOTALL), so you can make use of it.

Note that for Python, . excludes only \n. For other languages, it may excludes more: Javascript.