yapf_diff

change only what was changed

install

with pipenv

pipenv install git+https://github.com/luxresearch/yapf-diff.git@master#egg=yapf-diff

with pip

pip install git+https://github.com/luxresearch/yapf-diff.git@master#egg=yapf-diff

in requirements.txt

# requirements.txt: for a fast download
https://github.com/luxresearch/yapf-diff/archive/master.tar.gz

should I use yapf_diff?

Only if formatting all the lines in your modified file(s) would cause an unacceptably big diff in your revision history. PEP 8 recommends keeping your code consistent with the surrounding code. yapf-diff guarantees consistency only within the lines touched within a diff.

• if you're the the one choosing how and when to lint, choose black for consistency and speed.
• if formatting entire file at a time is an option, use something like

git diff --name-only | xargs black # or yapf, if you need a custom format

usage

# usage: yapf-diff [-h] [-d] [--debug] [-i] [--from-git-diff [BASE_REF]]
#
# format only changed lines
#
# optional arguments:
#   -h, --help            show this help message and exit
#   -d, --diff            print the yapf args and produced diff
#   --debug               print the style yapf is picking up
#   -i, --in-place        modify the changed files
#   --from-git-diff [BASE_REF]
#                         if used as a flag, this indicates that stdin is from
#                         git diff. If used as an argument, it indicates a ref
#                         against which to call git diff

# examples:
git diff origin/master | python -m yapf-diff --diff
python -m yapf-diff --from-git-diff="$(git log --merges -n 1)" --diff

Credit where credit is due

This module modifies a function from pycodestyle, which is under an MIT license. Their license is included within ./src/lib.py. Thanks to the PyCQA team for doing a much better job at unified diff parsing than my initial implementation.

See also:

• https://github.com/hayd/pep8radius
• https://gist.github.com/mwek/59aefeefc812dea39c93c068eb30b491