[Tutor] streamlining a return statement

[Erik Price]

I have a function in a chunk of code that detects the presence of HTML 
attributes in a string.  If successful, the function returns a tuple 
(containing 3 elements:  the whitespace preceding the tag, the tag 
element name itself, and a string containing all of the attributes of 
the element).

It works fine.  But I'm wondering whether returning an empty tuple is a 
good idea.  It feels like I should make use of Python's exception 
facilities.  (Right now the client code which uses this function works 
by calling len() on the return value of the function, but I could 
modify that to handle some kind of IndexError exception or whichever 
exception is appropriate.)

Can someone criticize my code please?  Specifically the "return" 
statements -- the first part of the function is just the way I want it. 
  Also, using "if matchobj" works but is that the preferred way to 
detect whether a re.search() was successful?  (Testing for successful 
assignment, "if matchobj = re.search()", which I admit is a Perlish way 
of looking at it, doesn't work.)

def atts_detect(line):
	"""searches a line for a tag with attributes and
	returns a tuple of info about the tag if attributes are found"""
	
	import re
	
	# this regex ensures that the tag the kind we want
	needle = r'(\s*)<(\w+)(\s+[-\w]+=[\'"].+[\'"])+(\s*/?>)'
	regex = re.compile(needle)
	
	# a match object is only returned if search is successful
	matchobj = regex.search(line)
	if matchobj: return matchobj.groups()
	# return an empty tuple if no matches found
	else: return ()


Thanks,
Erik


--
Erik Price

email: erikprice@mac.com
jabber: erikprice@jabber.org