Duplicate finder

gistfile1.py

#!/usr/bin/python2.7
import subprocess
from collections import defaultdict
from glob import glob
import sys

pattern = sys.argv[1]

d = defaultdict(lambda: [])

filenames = subprocess.check_output("find . -type f -name '{}' -print0 2>/dev/null; exit 0".format(pattern), shell=True).split('\0')
for filename in filenames:
    if len(filename) == 0:
        continue

    md5 = subprocess.check_output(["md5sum", filename]).split()[0]
    d[md5].append(filename)

print "Groups below (grouped by =======) are exact dupl."
for key in d.keys():
    if len(d[key]) >= 2:
        print '===================================='
        for value in d[key]:
            print value