Reads dates from git and updates CHANGELOG entries From pytest-dev/pytest#721

apply_dates.py

from __future__ import absolute_import, division, print_function, unicode_literals

import re
import subprocess

with open('CHANGELOG.rst') as f:
    changelog_lines = f.readlines()

output = subprocess.check_output('git log --tags --simplify-by-decoration --pretty="format:%ci %d"', shell=True)
tags_and_dates = {}
for line in output.splitlines():
    m = re.search('\(tag: (.*)\)', line)
    if not m:
        continue
    tag = m.group(1)

    date = line.split()[0]
    tags_and_dates[tag] = date

for index, changelog_line in enumerate(changelog_lines):
    if changelog_line.strip() in tags_and_dates:
        tag = changelog_line.strip()
        date = tags_and_dates[tag]
        new_line = '{} ({})\n'.format(tag, date)
        changelog_lines[index] = new_line
        changelog_lines[index + 1] = (len(new_line) - 1) * '=' + '\n'
        print(new_line)
        print(len(new_line) * '=')
        print()

with open('CHANGELOG.rst', 'w') as f:
    f.writelines(changelog_lines)