You can use autopep8! Whilst you make yourself a cup of coffee this tool happily removes all those pesky PEP8 violations which don't change the meaning of the code.
Install it via pip:
pip install autopep8
Apply this to a specific file:
autopep8 py_file --in-place
or to your project (recursively), the verbose option gives you some feedback of how it's going:
autopep8 project_dir --recursive --in-place --pep8-passes 2000 --verbose
Note: Sometimes the default of 100 passes isn't enough, I set it to 2000 as it's reasonably high and will catch all but the most troublesome files (it stops passing once it finds no resolvable pep8 infractions)...
At this point I suggest retesting and doing a commit!
If you want "full" PEP8 compliance: one tactic I've used is to run autopep8 as above, then run PEP8, which prints the remaining violations (file, line number, and what):
pep8 project_dir --ignore=E501
and manually change these individually (e.g. E712s - comparison with boolean).
Note: autopep8 offers an --aggressive argument (to ruthlessly "fix" these meaning-changing violations), but beware if you do use aggressive you may have to debug... (e.g. in numpy/pandas True == np.bool_(True) but not True is np.bool_(True)!)
You can check how many violations of each type (before and after):
pep8 --quiet --statistics .
Note: I consider E501s (line too long) are a special case as there will probably be a lot of these in your code and sometimes these are not corrected by autopep8.
As an example, I applied this technique to the pandas code base.
Answer from Andy Hayden on Stack OverflowVideos
Hello everyone!
I'm interested in formatting my code so that it matches PEP 8 guidelines. I've read through PEP 8, but as you can imagine, referencing the documentation and checking my code for format is pretty time consuming.
I know that it is possible to install extensions that do this automatically in VSCode, but in order to learn best practices, I actually want to make the code changes myself.
I did some searching through the VSCode docs, but I wasn't able to find quite what I was looking for. Here's what I want:
-
A formatter which runs every time the file is saved
-
I do not want it to make any changes automatically
-
I want all the non-compliant code to be listed somewhere like the "Problems" tab in the terminal window.
-
If it adds non-intrusive squiggles in my code that's a plus (especially if I can toggle to hide it)
-
Ideally verbose enough that I know what the issue is
-
If there is links to the relevant PEP 8 guideline in the output that would be great as well.
Does anything like this exist? I'm sure the popular tools already do what I'm looking for, but I wasn't able to figure out how to configure it to the way I want. Surprisingly, there's a lot more people are looking to make the formatting less manual, not more. :)
Thank you all!
You can use autopep8! Whilst you make yourself a cup of coffee this tool happily removes all those pesky PEP8 violations which don't change the meaning of the code.
Install it via pip:
pip install autopep8
Apply this to a specific file:
autopep8 py_file --in-place
or to your project (recursively), the verbose option gives you some feedback of how it's going:
autopep8 project_dir --recursive --in-place --pep8-passes 2000 --verbose
Note: Sometimes the default of 100 passes isn't enough, I set it to 2000 as it's reasonably high and will catch all but the most troublesome files (it stops passing once it finds no resolvable pep8 infractions)...
At this point I suggest retesting and doing a commit!
If you want "full" PEP8 compliance: one tactic I've used is to run autopep8 as above, then run PEP8, which prints the remaining violations (file, line number, and what):
pep8 project_dir --ignore=E501
and manually change these individually (e.g. E712s - comparison with boolean).
Note: autopep8 offers an --aggressive argument (to ruthlessly "fix" these meaning-changing violations), but beware if you do use aggressive you may have to debug... (e.g. in numpy/pandas True == np.bool_(True) but not True is np.bool_(True)!)
You can check how many violations of each type (before and after):
pep8 --quiet --statistics .
Note: I consider E501s (line too long) are a special case as there will probably be a lot of these in your code and sometimes these are not corrected by autopep8.
As an example, I applied this technique to the pandas code base.
Unfortunately "pep8 storming" (the entire project) has several negative side-effects:
- lots of merge-conflicts
- break git blame
- make code review difficult
As an alternative (and thanks to @y-p for the idea), I wrote a small package which autopep8s only those lines which you have been working on since the last commit/branch:
Basically leaving the project a little better than you found it:
pip install pep8radius
Suppose you've done your work off of master and are ready to commit:
# be somewhere in your project directory
# see the diff with pep, see the changes you've made since master
pep8radius master --diff
# make those changes
pep8radius master --diff --in-place
Or to clean the new lines you've commited since the last commit:
pep8radius --diff
pep8radius --diff --in-place
# the lines which changed since a specific commit `git diff 98f51f`
pep8radius 98f51f --diff
Basically pep8radius is applying autopep8 to lines in the output of git/hg diff (from the last shared commit).
This script currently works with git and hg, if your using something else and want this to work please post a comment/issue/PR!
autopep8
autopep8 would auto-format your python script. not only the code indentation, but also other coding spacing styles. It makes your python script to conform PEP8 Style Guide.
pip install autopep8
autopep8 your_script.py # dry-run, only print
autopep8 -i your_script.py # replace content
Update:
Many editors have pep8 plugins that automatically reformat your code right after you save the file. py-autopep8 in emacs
yapf
yapf is a new and better python code formatter. which tries to get the best formatting, not just to conform the guidelines. The usage is quite the same as autopep8.
pip install yapf
yapf your_script.py # dry-run, only print
yapf -i your_script.py # replace content
For more information, like formatting configurations, please read the README.rst on yapf github
Update 2:
Black
Black is much better than yapf. It's smarter and fits most complex formatting cases.
Edit: Nowadays, I would recommend autopep8, since it not only corrects indentation problems but also (at your discretion) makes code conform to many other PEP8 guidelines.
Use reindent.py. It should come with the standard distribution of Python, though on Ubuntu you need to install the python2.6-examples package.
You can also find it on the web.
This script attempts to convert any python script to conform with the 4-space standard.