Choose Python function to call based on a regex

This is based on Udi’s nice answer.

I think that the difficulty of creating anonymous functions is a bit of a red herring. What you really want to do is to keep related code together, and make the code neat. So I think decorators may work for you.

import re

# List of pairs (regexp, handler)
handlers = []

def handler_for(regexp):
    """Declare a function as handler for a regular expression."""
    def gethandler(f):
        handlers.append((re.compile(regexp), f))
        return f
    return gethandler

@handler_for(r'^<\w+> (.*)')
def handle_message(msg):
    print msg

@handler_for(r'^\*{3} (.*)')
def handle_warning(msg):
    global num_warnings, num_fatals
    num_warnings += 1
    if is_fatal(msg):
        num_fatals += 1