How do I use asterisk in lookbehind regex in python? -

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my test string:

1. default, no   hair, w/o glass 2. ski suit 3. swim suit

how detect if there "no" or "w/o" before hair (there more 1 spaces in between)?

the final goal:

1. default, no   hair, w/o glass    returns false 1. default, no hair, w/o glass    returns false 1. default, w/o hair, w/o glass    returns false 1. default, w hair, w/o glass    returns true

the goal tell whether glass should used or not.

my attempt: (?<!no\s)hair (http://rubular.com/r/pdkbmyxpgh)

you can see in above example, if there more 1 space, regex won't work.

the re module not support variable length (zero width) look-behind.

you need either:

  • fixed number of spaces before hair

  • use regex module

short function using negative lookahead:

def re_check(s):     return re.search(r'^[^,]+,\s+(?!(?:no|w/o)\s+hair,)', s) not none  >>> re_check('default, no   hair, w/o glass') false >>> re_check('default, w/o hair, w/o glass') false >>> re_check('default, w hair, w/o glass') true

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