def main()

in merge_pr.py [0:0]
92 lines of code
21 McCabe index (conditional complexity)

def main():
    global original_head

    os.chdir(GRIFFIN_HOME)
    original_head = get_current_ref()

    check_init()

    # Check this up front to avoid failing the JIRA update at the very end
    if not JIRA_USERNAME or not JIRA_PASSWORD:
        continue_maybe("The env-vars JIRA_USERNAME and/or JIRA_PASSWORD are not set. Continue?")

    branches = get_json("%s/branches" % GITHUB_API_BASE)
    branch_names = list(filter(lambda x: True, [x['name'] for x in branches]))
    # Assumes branch names can be sorted lexicographically
    latest_branch = sorted(branch_names, reverse=True)[0]

    pr_num = input("Which pull request would you like to merge? (e.g. 34): ")
    pr = get_json("%s/pulls/%s" % (GITHUB_API_BASE, pr_num))
    pr_events = get_json("%s/issues/%s/events" % (GITHUB_API_BASE, pr_num))

    url = pr["url"]

    # Warn if the PR is WIP
    if "[WIP]" in pr["title"]:
        msg = "The PR title has `[WIP]`:\n%s\nContinue?" % pr["title"]
        continue_maybe(msg)

    # Decide whether to use the modified title or not
    modified_title = standardize_jira_ref(pr["title"]).rstrip(".")
    if modified_title != pr["title"]:
        print("I've re-written the title as follows to match the standard format:")
        print("Original: %s" % pr["title"])
        print("Modified: %s" % modified_title)
        result = input("Would you like to use the modified title? (y/n): ")
        if result.lower() == "y":
            title = modified_title
            print("Using modified title:")
        else:
            title = pr["title"]
            print("Using original title:")
        print(title)
    else:
        title = pr["title"]

    modified_body = re.sub(re.compile(r'<!--[^>]*-->\n?', re.DOTALL), '', pr["body"]).lstrip()
    if modified_body != pr["body"]:
        print("=" * 80)
        print(modified_body)
        print("=" * 80)
        print("I've removed the comments from PR template like the above:")
        result = input("Would you like to use the modified body? (y/n): ")
        if result.lower() == "y":
            body = modified_body
            print("Using modified body:")
        else:
            body = pr["body"]
            print("Using original body:")
        print("=" * 80)
        print(body)
        print("=" * 80)
    else:
        body = pr["body"]
    target_ref = pr["base"]["ref"]
    user_login = pr["user"]["login"]
    base_ref = pr["head"]["ref"]
    pr_repo_desc = "%s/%s" % (user_login, base_ref)

    # Merged pull requests don't appear as merged in the GitHub API;
    # Instead, they're closed by asfgit.
    merge_commits = \
        [e for e in pr_events if e["actor"]["login"] == "asfgit" and e["event"] == "closed"]

    if merge_commits:
        merge_hash = merge_commits[0]["commit_id"]
        message = get_json("%s/commits/%s" % (GITHUB_API_BASE, merge_hash))["commit"]["message"]

        print("Pull request %s has already been merged, assuming you want to backport" % pr_num)
        commit_is_downloaded = run_cmd(['git', 'rev-parse', '--quiet', '--verify',
                                        "%s^{commit}" % merge_hash]).strip() != ""
        if not commit_is_downloaded:
            fail("Couldn't find any merge commit for #%s, you may need to update HEAD." % pr_num)

        print("Found commit %s:\n%s" % (merge_hash, message))
        cherry_pick(pr_num, merge_hash, latest_branch)
        sys.exit(0)

    if not bool(pr["mergeable"]):
        msg = "Pull request %s is not mergeable in its current form.\n" % pr_num + \
              "Continue? (experts only!)"
        continue_maybe(msg)

    print("\n=== Pull Request #%s ===" % pr_num)
    print("title\t%s\nsource\t%s\ntarget\t%s\nurl\t%s" %
          (title, pr_repo_desc, target_ref, url))
    continue_maybe("Proceed with merging pull request #%s?" % pr_num)

    merged_refs = [target_ref]

    merge_hash = merge_pr(pr_num, target_ref, title, body, pr_repo_desc)

    pick_prompt = "Would you like to pick %s into another branch?" % merge_hash
    while input("\n%s (y/n): " % pick_prompt).lower() == "y":
        merged_refs = merged_refs + [cherry_pick(pr_num, merge_hash, latest_branch)]

    if JIRA_IMPORTED:
        if JIRA_USERNAME and JIRA_PASSWORD:
            continue_maybe("Would you like to update an associated JIRA?")
            jira_comment = "Issue resolved by pull request %s\n[%s/%s]" % \
                           (pr_num, GITHUB_BASE, pr_num)
            resolve_jira_issues(title, merged_refs, jira_comment)
        else:
            print("JIRA_USERNAME and JIRA_PASSWORD not set")
            print("Exiting without trying to close the associated JIRA.")
    else:
        print("Could not find jira-python library. Run 'sudo pip3 install jira' to install.")
        print("Exiting without trying to close the associated JIRA.")