autoflake removes unused imports and unused variables from Python code. It makes use of pyflakes to do this.
By default, autoflake only removes unused imports for modules that are part of the standard library. (Other modules may have side effects that make them unsafe to remove automatically.) Removal of unused variables is also disabled by default.
autoflake also removes useless pass
statements.
Running autoflake on the below example:
$ autoflake --in-place --remove-unused-variables example.py
import math
import re
import os
import random
import multiprocessing
import grp, pwd, platform
import subprocess, sys
def foo():
from abc import ABCMeta, WeakSet
try:
import multiprocessing
print(multiprocessing.cpu_count())
except ImportError as exception:
print(sys.version)
return math.pi
results in
import math
import sys
def foo():
try:
import multiprocessing
print(multiprocessing.cpu_count())
except ImportError:
print(sys.version)
return math.pi
$ pip install --upgrade autoflake
To allow autoflake to remove additional unused imports (other than than those from the standard library), use the --imports
option. It accepts a comma-separated list of names:
$ autoflake --imports=django,requests,urllib3 <filename>
To remove all unused imports (whether or not they are from the standard library), use the --remove-all-unused-imports
option.
To remove unused variables, use the --remove-unused-variables
option.
Below is the full listing of options:
usage: autoflake [-h] [-i] [-r] [--exclude globs] [--imports IMPORTS]
[--expand-star-imports] [--remove-all-unused-imports]
[--remove-duplicate-keys] [--remove-unused-variables]
[--version]
files [files ...]
Removes unused imports and unused variables as reported by pyflakes.
positional arguments:
files files to format
optional arguments:
-h, --help show this help message and exit
-i, --in-place make changes to files instead of printing diffs
-s, --stdout print changed text to STDOUT
-r, --recursive drill down directories recursively
--exclude globs exclude file/directory names that match these comma-
separated globs
--imports IMPORTS by default, only unused standard library imports are
removed; specify a comma-separated list of additional
modules/packages
--expand-star-imports
expand wildcard star imports with undefined names;
this only triggers if there is only one star import in
the file; this is skipped if there are any uses of
`__all__` or `del` in the file
--remove-all-unused-imports
remove all unused imports (not just those from the
standard library)
--remove-duplicate-keys
remove all duplicate keys in objects
--remove-unused-variables
remove unused variables
--version show program's version number and exit
To run the unit tests:
$ ./test_autoflake.py
There is also a fuzz test, which runs against any collection of given Python files. It tests autoflake against the files and checks how well it does by running pyflakes on the file before and after. The test fails if the pyflakes results change for the worse. (This is done in memory. The actual files are left untouched.):
$ ./test_fuzz.py --verbose