level3.py

# Python Challenge level 3
# Hint: One small letter, surrounded by EXACTLY three big bodyguards on each of its sides.
# Data found in source of web-page, put in level3.txt

# Problem similar to level2

import re

def main():
 #load file to string
 file = open('level3.txt')
 str = ''.join([line for line in file])

 # find all occurencies and fetch a small letter

 small = re.findall(r'[a-z][A-Z]{3}([a-z]{1})[A-Z]{3}[a-z]', str)
 print "".join(small)

# linkedlist

main()