How do I search through regex matches in Python?

python, regex, switch-statement

Solution

def doit( s ):

    # with some side-effect on a
    a = [] 

    def f1( s, m ):
        a.append( 1 )
        print 'f1', a, s, m

    def f2( s, m ):
        a.append( 2 )
        print 'f2', a, s, m

    def f3( s, m ):
        a.append( 3 )
        print 'f3', a, s, m

    re1 = re.compile( 'one' )
    re2 = re.compile( 'two' )
    re3 = re.compile( 'three' )


    func_re_list = (
        ( f1, re1 ), 
        ( f2, re2 ), 
        ( f3, re3 ),
    )
    for myfunc, myre in func_re_list:
        m = myre.match( s )
        if m:
            myfunc( s, m )
            break


doit( 'one' ) 
doit( 'two' ) 
doit( 'three' )

Problem

I need to try a string against multiple (exclusive - meaning a string that matches one of them can't match any of the other) regexes, and execute a different piece of code depending on which one it matches. What I have currently is: ``` m = firstre.match(str) if m: # Do something m = secondre.match(str) if m: # Do something else m = thirdre.match(str) if m: # Do something different from both ``` Apart from the ugliness, this code matches against all regexes even after it has matched one of them (say firstre), which is inefficient. I tried to use: ``` elif m = secondre.match(str) ``` but learnt that assignment is not allowed in if statements. Is there an elegant way to achieve what I want?

Original source