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=========
autoflake
=========
.. image:: https://travis-ci.org/myint/autoflake.svg?branch=master
:target: https://travis-ci.org/myint/autoflake
:alt: Build status
Introduction
============
*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.
.. _pyflakes: http://pypi.python.org/pypi/pyflakes
Example
=======
Running autoflake on the below example::
$ autoflake --in-place --remove-unused-variables example.py
.. code-block:: python
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
.. code-block:: python
import math
import sys
def foo():
try:
import multiprocessing
print(multiprocessing.cpu_count())
except ImportError:
print(sys.version)
return math.pi
Installation
============
::
$ pip install --upgrade autoflake
Advanced usage
==============
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
Tests
=====
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
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.
For example:
.. code-block:: python
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:
.. code-block:: python
from .endpoints import role, token, user, utils # noqa
That line will instruct ``autoflake`` to let that specific line as is.