Getting average value of recursively read integers from files

average_int_from_files.py

import re


def get_numbers(filename):
    numbers = []

    try:
        f = open(filename, 'r')
    except IOError:
        return numbers

    for line in f:
        line = line.strip()
        if not line:
            continue
        if re.search('[^\d]+', line):
            numbers.extend(get_numbers(line))
        else:
            numbers.append(int(line))
    return numbers


def average(filename):
    numbers = get_numbers(filename)
    avg = numbers and float(sum(numbers)) / len(numbers) or 0
    return avg


if __name__ == '__main__':
    print average('testfile2323.txt')