Build a dictionary from successful regex matches in python

Question

I'm pretty new to Python, and I'm trying to parse a file. Only certain lines in the file contain data of interest, and I want to end up with a dictionary of the stuff parsed from valid matching lines in the file.

The code below works, but it's a bit ugly and I'm trying to learn how it should be done, perhaps with a comprehension, or else with a multiline regex. I'm using Python 3.2.

file_data = open('x:\\path\\to\\file','r').readlines()
my_list = []
for line in file_data:
    # discard lines which don't match at all
    if re.search(pattern, line):
        # icky, repeating search!!
        one_tuple = re.search(pattern, line).group(3,2)
        my_list.append(one_tuple)
my_dict = dict(my_list)

Can you suggest a better implementation?

Answer 1

Thanks for the replies. After putting them together I got

file_data = open('x:\\path\\to\\file','r').read()
my_list = re.findall(pattern, file_data, re.MULTILINE)
my_dict = {c:b for a,b,c in my_list}

but I don't think I could have gotten there today without the help.