Push new local branch to remote using Gitpython

Question

I looked at a few references but I am still having problems:

I want to clone a remote repo, create a new branch, and push the new branch back to remote using GitPython.

This seems to work:

import git
import subprocess

nm_brnch = 'new_branch'

# Clone    
repo_url = r'my_remote.git'
repo = git.Repo.clone_from(repo_url, dnm_wrk, branch=r'some_branch')

# Create new branch
git = repo.git
git.checkout('HEAD', b=nm_brnch)

# Push new branch to remote
subprocess.call(f'git push -u origin {nm_brnch}')

But it's ugly, since it uses subprocess, instead of using GitPython.

I tried using GitPython, but without success:

repo.head.set_reference(nm_brnch)
repo.git.push("origin", nm_brnch)

I have consulted the following references:

• Pushing local branch to remote branch

• Use GitPython to Checkout a new branch and push to remote

• Related GitHub issue/question

• Tutorial from official docs

Answer 1

I'm using gitpython==2.1.11 with Python 3.7. Below is my push function in which I first try a high-level push, and then a low-level push as necessary. Note how I check the return value of either command. I also log the push actions, and this explains what's happening at every step.

class GitCommandError(Exception):
    pass

class Git:
    def _commit_and_push_repo(self) -> None:
        repo = self._repo
        remote = repo.remote()
        remote_name = remote.name
        branch_name = repo.active_branch.name

        # Note: repo.index.entries was observed to also include unpushed files in addition to uncommitted files.
        log.debug('Committing repository index in active branch "%s".', branch_name)
        self._repo.index.commit('')
        log.info('Committed repository index in active branch "%s".', branch_name)

        def _is_pushed(push_info: git.remote.PushInfo) -> bool:
            valid_flags = {push_info.FAST_FORWARD, push_info.NEW_HEAD}  # UP_TO_DATE flag is intentionally skipped.
            return push_info.flags in valid_flags  # This check can require the use of & instead.

        push_desc = f'active branch "{branch_name}" to repository remote "{remote_name}"'
        log.debug('Pushing %s.', push_desc)
        try:
            push_info = remote.push()[0]
        except git.exc.GitCommandError:  # Could be due to no upstream branch.
            log.warning('Failed to push %s. This could be due to no matching upstream branch.', push_desc)
            log.info('Reattempting to push %s using a lower-level command which also sets upstream branch.', push_desc)
            push_output = repo.git.push('--set-upstream', remote_name, branch_name)
            log.info('Push output was: %s', push_output)
            expected_msg = f"Branch '{branch_name}' set up to track remote branch '{branch_name}' from '{remote_name}'."
            if push_output != expected_msg:
                raise RepoPushError(f'Failed to push {push_desc}.')
        else:
            is_pushed = _is_pushed(push_info)
            logger = log.debug if is_pushed else log.warning
            logger('Push flags were %s and message was "%s".', push_info.flags, push_info.summary.strip())
            if not is_pushed:
                log.warning('Failed first attempt at pushing %s. A pull will be performed.', push_desc)
                self._pull_repo()
                log.info('Reattempting to push %s.', push_desc)
                push_info = remote.push()[0]
                is_pushed = _is_pushed(push_info)
                logger = log.debug if is_pushed else log.error
                logger('Push flags were %s and message was "%s".', push_info.flags, push_info.summary.strip())
                if not is_pushed:
                    raise RepoPushError(f'Failed to push {push_desc} despite a pull.')
        log.info('Pushed %s.', push_desc)