Excellent work. I thought this problem demanded more legwork than other days. And those line breaks! (I used Vim, to remove single newlines and reduce doubles to a single). For the "chain of ands" problem, I tried something like: def check_validity(passport) keys=[ "byr:" , "iyr:" , "eyr:" , "hgt:" , "hcl:" , "ecl:" , "pid:" ] for test in keys: if test in passport: pass else : return False return True