line_checksummer.py

#!/usr/bin/env python
"""Read from stdin and print chunks with checksums."""

from __future__ import print_function
import sys
import md5

chunk_size = 40

def part_str(s, l):
  """Partition string s into chunks of size l, potentially ragged at end."""
  ret = []
  while len(s) > 0:
    ret.append(s[:l])
    s = s[l:]
  return ret

def main():
  print("Delimiters [ and ], newline ...")
  for line in sys.stdin.readlines():
    line = line.rstrip("\r\n")
    for chunk in part_str(line, chunk_size):
      checksum = md5.md5(chunk).hexdigest()
      fixchunk = ("[" + chunk + "]").ljust(45, " ")
      print("%s %s" % (fixchunk, checksum))
    print("...")

if __name__ == '__main__':
  main()