Question

Possible Duplicate:
Check if a variable is SRE_Match

I need to determine if the parameter passed to a function is a regular expression match type or not. Currently I have:

re_type = type(re.compile(''))

def func(result):
    if isinstance(result, re_type):
        print("re")

However, I can never get it to print re. When I print result, I get:

<_sre.SRE_Match object at 0x7fed5330>

Is there an easier way to recognize this object?

Answer 1

Change first line to:

re_type = type(re.match('', ''))

Currently you have the re_type set to the type of a regular expression, not the match that results from the application of a regular expression to input.

Note also that the re module will return None where there is no match, so if your function really only expects a match type or None, you might just do:

def func(result):
   if result:
      # do stuff...

Lastly, you may be violating the EAFP principle of Python. This last version assumes result is a match type unless something breaks…

def func(result):
    try:
        for group in result.groups():
            # handle match group
    except AttributeError:
       # Looks like this wasn't a real match object