Python 0 wide Negative lookahead assertion (experience)

0 wide (surround) negative lookahead assertion (negative Forward View assertion): (?! EXP), which asserts that the expression cannot be matched before this position, so it will only match the location where the suffix exp does not exist.

0 width, indicating that it is not a character width.

Ex:

1>>>Import re2>>>['sale%s'% E.group (2) forEinch 3Re.finditer (R'(? m) ^\s+ (?! noreply) (\w+) (@\w+\.\w+)',4          " "5 [email protected]6 [email protected]7 [email protected]8 [email protected]9               " ")]Ten['[email protected]','[email protected]','[email protected]']

Wherein, R ' (? m) ^\s+ (?! noreply) (\w+) (@\w+\.\w+) '

(? m) on behalf of multiline, multi-line search.

^\s+ represents the number of spaces placed at the beginning of a sentence.

(?! Noreply) represents an expression that cannot be matched if there is a suffix noreply.

(\w+) Match mail user name

(\w+) (@\w+\.\w+) match mail domain name

Group (1) represents user name (below)

Group (2) represents the domain name

['sale%s'% E.group (1) forEinchRe.finditer (R'(? m) ^\s+ (?! noreply) (\w+) (@\w+\.\w+)',         " "[email protected] [email protected] [email protected] [email prot Ected]" ")]['Salesales','Salepostmaster','Saleeng']

Thank:

http://blog.csdn.net/firetaker/article/details/5603756

http://blog.csdn.net/binjly/article/details/12152235

Python 0 wide Negative lookahead assertion (experience)