Duplicate file detector

import os, hashlib
path = "<PATH>/"

files = {}
yup = {}

for file in os.listdir(path):

  file = path+file

  hash = hashlib.md5(open(file, "rb").read()).hexdigest()
  if hash in files.values():
    yup[file] = hash
  else:
    files[file] = hash

def outputToFile():
  # Write shit to a text file.
  with open("outf.txt", "w") as out:
    for i in yup:
      out.write("{} - {}\n".format(i, yup[i]))