Composing regex from a list

[Steven D'Aprano]

On Thu, 16 Jun 2011 20:48:46 +0800, TheSaint wrote:

> Hello,
> Is it possible to compile a regex by supplying a list?
> 
> lst= ['good', 'brilliant'. 'solid']
> 
> re.compile(r'^'(any_of_lst))
> 
> without to go into a *for* cicle?


How about this?


def compile_alternatives(*args):
    alternatives = map(lambda s: '(' + s + ')', args)
    alternatives = '|'.join(alternatives)
    return re.compile(alternatives)


>>> x = compile_alternatives('spam', 'ham', 'cheese')
>>> x.search('fried egg and spam').group()
'spam'



-- 
Steven