Simple script that looks for issue/pr references in commit messages, and generates something like a changelog

changelog.py

#!/usr/bin/env python

import os
import re

import mistune  # mistune

from github import Github  # PyGithub
from argparse import ArgumentParser


MD_ITEM = '''
* **%s**
  * [%s](%s)
'''


parser = ArgumentParser()
parser.add_argument('repo', help='Repository in the format of :owner/:repo')
parser.add_argument('--base', default='master',
                    help='Base branch to compare (default: %(default)s)')
parser.add_argument('--head', default='staging',
                    help='HEAD branch to compare (default: %(default)s)')
parser.add_argument('--token', default=os.getenv('GITHUB_TOKEN'),
                    help='Github Oauth Token (default: GITHUB_TOKEN')
parser.add_argument('--format', choices=('plain', 'markdown', 'html'),
                    default='plain',
                    help='Output format (default: %(default)s)')
args = parser.parse_args()

g = Github(base_url='https://api.github.com',
           login_or_token=args.token,
           per_page=100)


KEYWORD_RE = re.compile('#(\d+)', flags=re.I)

repo = g.get_repo(args.repo)
issues = set()

for c in repo.compare(args.base, args.head).commits:
    message = c.commit.message

    kw_matches = KEYWORD_RE.findall(message)

    if kw_matches:
        issues.update(kw_matches)

dups = []
out = []
for number in sorted(map(int, issues)):
    number = int(number)
    if number in dups:
        continue

    issue = repo.get_issue(number)

    dups.append(issue.number)

    if args.format == 'plain':
        out.append('#%d %s' % (issue.number, issue.title))
    else:
        out.append(MD_ITEM % (issue.title, issue.html_url, issue.html_url))
    dups.append(issue.number)

if args.format == 'html':
    print(mistune.markdown('\n'.join(out)))
else:
    print('\n'.join(out))