Shows commits present only in one of the two branches.

git-diff-branches.py

#!/usr/bin/python
# Shows commits present only in one of the two branches.

import commands
import sys

def commits_in_branch(branch):
    status, output = commands.getstatusoutput("git log --no-color --pretty=oneline %s" % branch)
    return set(output.splitlines())

def print_diff(br1name, br1, br2name, br2):
    print "Commits in %s, but not in %s:" % (br1name, br2name)
    print '\n'.join(br1 - br2)

if len(sys.argv) < 3:
    print "usage:\n    git-diff-branches branch1 branch2"
else:
    br1name, br2name = sys.argv[1:3]
    br1 = commits_in_branch(br1name)
    br2 = commits_in_branch(br2name)
    print_diff(br1name, br1, br2name, br2)