Script to comment on all open Ray pull requests.

comment.py

import time

from github import Github

MESSAGE = """
## :bangbang: ACTION REQUIRED :bangbang:

We've switched our code formatter from YAPF to Black (see #21311).

To prevent issues with merging your code, here's what you'll need to do:

1. Install Black
```
pip install -I black==21.12b0
```

2. Format changed files with Black
```
curl -o format-changed.sh https://gist.githubusercontent.com/bveeramani/42ef0e9e387b755a8a735b084af976f2/raw/7631276790765d555c423b8db2b679fd957b984a/format-changed.sh
chmod +x ./format-changed.sh
./format-changed.sh
rm format-changed.sh
```

3. Commit your changes.
```
git add --all
git commit -m "Format Python code with Black"
```

4. Merge master into your branch.
```
git pull upstream master
```

5. Resolve merge conflicts (if necessary).

After running these steps, you'll have the updated `format.sh`.
"""

ACCESS_TOKEN = ...

github_client = Github(ACCESS_TOKEN)
ray_repo = github_client.get_repo("ray-project/ray")
for pull_request in ray_repo.get_pulls(state="open"):
    pull_request.create_issue_comment(body=MESSAGE)
    time.sleep(5)  # To avoid rate limits

We've switched our code style from PEP8 to Black (see #21311)

Alternatively: ... our code formatter from Yapf to Black.