PFA (Python Fast Autoformat)
An autoformatter should be three things:
- Fast: Run quickly so that you can afford to run the autoformatter on a large code base without ever having to wait for the autoformat to complete.
- Consistent: Running the autoformatter a second time won't change the output. Code will run the same before and after the autoformatter is run. Trivial whitespace changes will be reverted.
- Pretty: Output looks nice and preferably follows PEP8.
PFA chooses to be Fast and Consistent, but sacrifices Pretty output in favor of speed.
Installation and Usage
To create the executable file
Afterwards you can copy it into
PATH, say to
There are two ways to run the program. If the executable file name does not end in "i", i.e. with
then the formatted file will be dumped to standard output. If you make a symlink from
pfai and run the latter like
pfai that_python_script.py scriptus_secundus.py
then all files listed as arguments will be formatted in place.
Why is PFA written in C? The startup time for the Python interpreter is often longer than it takes to run
pfaon a 2000 line file.
How fast is it? The other popular Python formatters are
autopep8. Formatting about 120KB of python code in place for the second time in a row with the following commands,
yapf -i bx.py autopep8 -i bx.py pfai bx.py
one finds that
yapftakes 14.0 seconds;
autopep8takes 1.8 seconds; and
pfaicompletes in 0.020 seconds, less than the time it takes to press Enter.
I have a change to contribute. Will it be accepted?: Yes, as long as
pfastill runs in O(n) for even pathological input.