import re

sample = [
    'blah',
    'food',
    'test',
    'junk',
    'bazfool',
    'bark',
    'fodder']

def process(input):
    i = 0
    input_length = len(input)
    pattern = '.*foo.*'
    while (i < input_length):
        if re.match(pattern, input[i]) and i < (input_length - 1):
            yield input[i + 1]
            i += 2
        else:
            i += 1

for res in process(sample):
    print(res)