Python script to create grading pull requests. Requires Python3 and PyGithub.

create_grading_prs.py

#!/usr/bin/env python3 -O
#
# This script prepares to grade students homework submissions for a particular assignment.
# To do so, it creates a branch on each student's fork equivalent to the original assignment.
# It then creates a pull request against that branch.
#
# Author: Shilad Sen
#

import logging
import sys

from github import Github, UnknownObjectException, GithubException


def create_grading_pull_request(gh, repo_name):
    repo = gh.get_repo(repo_name)
    hashes = list(repo.get_commits())
    if len(hashes) <= 1:
        logging.warning("No commits found on repo %s", repo_name)
        return
    start_hash = hashes[-1].sha

    # Create the branch if it doesn't already exist
    branch = None
    try:
        branch = repo.get_git_ref("heads/start_code")
    except UnknownObjectException:
        branch = repo.create_git_ref("refs/heads/start_code", start_hash)

    pr = repo.create_pull(
        title='COMP 127 Grading Pull Request for ' + repo_name,
        body='Pull request for grading. You dont need to do anything!',
        base='refs/heads/start_code',
        head='refs/heads/master',
        maintainer_can_modify=True
    )



def get_last_shared_hash(gh, user, org, repo):
    uhashes = gh.get_history_hashes(user, repo)
    ohashes = gh.get_history_hashes(org, repo)
    latest = None
    for i in range(min(len(uhashes), len(ohashes))):
        if uhashes[i] == ohashes[i]:
            latest = uhashes[i]
        else:
            break
    return latest


if __name__ == '__main__':
    logging.basicConfig(level=logging.INFO)

    import argparse
    import getpass

    parser = argparse.ArgumentParser(description='Create pull requests for grading repo.')
    parser.add_argument('--repo', help='Repository prefix associated with the assignment (e.g. "mac-comp127-f19/127-hw0")', required=True)
    parser.add_argument('--student-file', help='File containing student github ids, one id per line', default=None)
    parser.add_argument('--student', help='student github name', default=[], action='append')
    parser.add_argument('--github-user', help='Your github username', required=True)
    parser.add_argument('--github-password', help='Your github password', default=None)

    args = parser.parse_args()

    students = []
    if args.student_file:
        with open(args.student_file) as f:
            students.extend([line.strip() for line in f])
    students.extend(args.student)
    students = sorted(set(students))

    if not students:
        logging.fatal("No students specified")
        parser.print_help()
        sys.exit(1)

    passwd = args.github_password if args.github_password else getpass.getpass('GitHub password:')
    gh = Github(args.github_user, passwd)

    logging.info("Creating pull requests using github user %s", args.github_user)
    logging.info("For changeset in repos prefixed by %s", args.repo)
    logging.info("For %d students ranging from %s to %s", len(students), students[0], students[-1])

    for student in students:
        student_repo = args.repo + '-' + student
        try:
            create_grading_pull_request(gh, student_repo)
            print('created pull request for ' + student)
        except UnknownObjectException:
            logging.warning("Student repository %s not found for student %s", student_repo, student)
        except GithubException as ghe:
            if 'pull request already exists' in str(ghe):
                print('Pull request already exists for ' + student)