How to use the changelog.main function in changelog

def commit(version):
    changelog.main(version)

    print "Adding and committing files..."
    addAndCommitReleaseFiles(version)

    print "Publishing new commit to master..."
    subprocess.call(('git push origin master').split(), stderr=subprocess.STDOUT, stdout=subprocess.PIPE)

    print "Publishing to NPM registry..."
    subprocess.call(('npm version %s' % version).split())
    subprocess.call(('npm publish').split())

    print "Push git repository..."
    subprocess.call(('git push origin %s' % version).split(), stderr=subprocess.STDOUT, stdout=subprocess.PIPE)

    print "Release %s created!" % version