code: def grep(pattern, filename):
      
      try:
          # for line in file
          # if line matches pattern:
          #    return line
          return next((L for L in open(filename) if L.find(pattern) >= 0))
      except StopIteration:
          return ''
docs: Very simple grep that returns the first matching line in a file.
      String matching only, does not do REs as currently implemented.