Removes unused imports and unused variables
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
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 -c, --check return error code if changes are needed -i, --in-place make changes to files instead of printing diffs -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:
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
Excluding specific lines
It might be the case that you have some imports for their side effects, even if you are not using them directly in that file.
That is common, for example, in Flask based applications. In where you import Python modules (files) that imported a main app, to have them included in the routes.
from .endpoints import role, token, user, utils
As those imports are not being used directly, if you are using the option --remove-all-unused-imports, they would be removed.
To prevent that, without having to exclude the entire file, you can add a # noqa comment at the end of the line, like:
from .endpoints import role, token, user, utils # noqa
That line will instruct autoflake to let that specific line as is.