How to correct TypeError: Unicode-objects must be encoded before hashing?

I have this error:

Traceback (most recent call last):
  File "python_md5_cracker.py", line 27, in <module>
  m.update(line)
TypeError: Unicode-objects must be encoded before hashing

when I try to execute this code in Python 3.2.2:

import hashlib, sys
m = hashlib.md5()
hash = ""
hash_file = input("What is the file name in which the hash resides?  ")
wordlist = input("What is your wordlist?  (Enter the file name)  ")
try:
  hashdocument = open(hash_file, "r")
except IOError:
  print("Invalid file.")
  raw_input()
  sys.exit()
else:
  hash = hashdocument.readline()
  hash = hash.replace("\n", "")

try:
  wordlistfile = open(wordlist, "r")
except IOError:
  print("Invalid file.")
  raw_input()
  sys.exit()
else:
  pass
for line in wordlistfile:
  # Flush the buffer (this caused a massive problem when placed 
  # at the beginning of the script, because the buffer kept getting
  # overwritten, thus comparing incorrect hashes)
  m = hashlib.md5()
  line = line.replace("\n", "")
  m.update(line)
  word_hash = m.hexdigest()
  if word_hash == hash:
    print("Collision! The word corresponding to the given hash is", line)
    input()
    sys.exit()

print("The hash given does not correspond to any supplied word in the wordlist.")
input()
sys.exit()

It is probably looking for a character encoding from wordlistfile.

wordlistfile = open(wordlist,"r",encoding='utf-8')

Or, if you're working on a line-by-line basis:

line.encode('utf-8')

EDIT

Per the comment below and this answer.

My answer above assumes that the desired output is a str from the wordlist file. If you are comfortable in working in bytes, then you're better off using open(wordlist, "rb"). But it is important to remember that your hashfile should NOT use rb if you are comparing it to the output of hexdigest. hashlib.md5(value).hashdigest() outputs a str and that cannot be directly compared with a bytes object: 'abc' != b'abc'. (There's a lot more to this topic, but I don't have the time ATM).

It should also be noted that this line:

line.replace("\n", "")

Should probably be

line.strip()

That will work for both bytes and str's. But if you decide to simply convert to bytes, then you can change the line to:

line.replace(b"\n", b"")