path: root/README.rst

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    :alt: isort

########

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isort your python imports for you so you don't have to.

isort is a Python utility / library to sort imports alphabetically, and automatically separated into sections.
It provides a command line utility, Python library and `plugins for various editors <https://github.com/timothycrosley/isort/wiki/isort-Plugins>`_ to quickly sort all your imports.
It currently cleanly supports Python 2.7 - 3.6 without any dependencies.

.. image:: https://raw.github.com/timothycrosley/isort/develop/example.gif
   :alt: Example Usage

Before isort:

.. code-block:: python

    from my_lib import Object

    print("Hey")

    import os

    from my_lib import Object3

    from my_lib import Object2

    import sys

    from third_party import lib15, lib1, lib2, lib3, lib4, lib5, lib6, lib7, lib8, lib9, lib10, lib11, lib12, lib13, lib14

    import sys

    from __future__ import absolute_import

    from third_party import lib3

    print("yo")

After isort:

.. code-block:: python

    from __future__ import absolute_import

    import os
    import sys

    from third_party import (lib1, lib2, lib3, lib4, lib5, lib6, lib7, lib8,
                             lib9, lib10, lib11, lib12, lib13, lib14, lib15)

    from my_lib import Object, Object2, Object3

    print("Hey")
    print("yo")

Installing isort
================

Installing isort is as simple as:

.. code-block:: bash

    pip install isort

or if you prefer

.. code-block:: bash

    easy_install isort

Using isort
===========

**From the command line**:

.. code-block:: bash

    isort mypythonfile.py mypythonfile2.py

or recursively:

.. code-block:: bash

    isort -rc .

*which is equivalent to:*

.. code-block:: bash

    isort **/*.py

or to see the proposed changes without applying them:

.. code-block:: bash

    isort mypythonfile.py --diff

Finally, to atomically run isort against a project, only applying changes if they don't introduce syntax errors do:

.. code-block:: bash

    isort -rc --atomic .

(Note: this is disabled by default as it keeps isort from being able to run against code written using a different version of Python)

**From within Python**:

.. code-block:: bash

    from isort import SortImports

    SortImports("pythonfile.py")

or:

.. code-block:: bash

    from isort import SortImports

    new_contents = SortImports(file_contents=old_contents).output

**From within Kate:**

.. code-block:: bash

    ctrl+[

or:

.. code-block:: bash

    menu > Python > Sort Imports

Installing isort's Kate plugin
==============================

For KDE 4.13+ / Pate 2.0+:

.. code-block:: bash

    wget https://raw.github.com/timothycrosley/isort/master/kate_plugin/isort_plugin.py --output-document ~/.kde/share/apps/kate/pate/isort_plugin.py
    wget https://raw.github.com/timothycrosley/isort/master/kate_plugin/isort_plugin_ui.rc --output-document ~/.kde/share/apps/kate/pate/isort_plugin_ui.rc
    wget https://raw.github.com/timothycrosley/isort/master/kate_plugin/katepart_isort.desktop --output-document ~/.kde/share/kde4/services/katepart_isort.desktop

For all older versions:

.. code-block:: bash

    wget https://raw.github.com/timothycrosley/isort/master/kate_plugin/isort_plugin_old.py --output-document ~/.kde/share/apps/kate/pate/isort_plugin.py

You will then need to restart kate and enable Python Plugins as well as the isort plugin itself.

Installing isort's for your preferred text editor
=================================================

Several plugins have been written that enable to use isort from within a variety of text-editors.
You can find a full list of them `on the isort wiki <https://github.com/timothycrosley/isort/wiki/isort-Plugins>`_.
Additionally, I will enthusiastically accept pull requests that include plugins for other text editors
and add documentation for them as I am notified.

How does isort work?
====================

isort parses specified files for global level import lines (imports outside of try / except blocks, functions, etc..)
and puts them all at the top of the file grouped together by the type of import:

- Future
- Python Standard Library
- Third Party
- Current Python Project
- Explicitly Local (. before import, as in: ``from . import x``)
- Custom Separate Sections (Defined by forced_separate list in configuration file)
- Custom Sections (Defined by sections list in configuration file)

Inside of each section the imports are sorted alphabetically. isort automatically removes duplicate python imports,
and wraps long from imports to the specified line length (defaults to 80).

When will isort not work?
=========================

If you ever have the situation where you need to have a try / except block in the middle of top-level imports or if
your import order is directly linked to precedence.

For example: a common practice in Django settings files is importing * from various settings files to form
a new settings file. In this case if any of the imports change order you are changing the settings definition itself.

However, you can configure isort to skip over just these files - or even to force certain imports to the top.

Configuring isort
=================

If you find the default isort settings do not work well for your project, isort provides several ways to adjust
the behavior.

To configure isort for a single user create a ``~/.isort.cfg`` file:

.. code-block:: ini

    [settings]
    line_length=120
    force_to_top=file1.py,file2.py
    skip=file3.py,file4.py
    known_future_library=future,pies
    known_standard_library=std,std2
    known_third_party=randomthirdparty
    known_first_party=mylib1,mylib2
    indent='    '
    multi_line_output=3
    length_sort=1
    forced_separate=django.contrib,django.utils
    default_section=FIRSTPARTY
    no_lines_before=LOCALFOLDER

Additionally, you can specify project level configuration simply by placing a ``.isort.cfg`` file at the root of your
project. isort will look up to 25 directories up, from the file it is ran against, to find a project specific configuration.

Or, if you prefer, you can add an isort section to your project's ``setup.cfg`` or ``tox.ini`` file with any desired settings.

You can then override any of these settings by using command line arguments, or by passing in override values to the
SortImports class.

Finally, as of version 3.0 isort supports editorconfig files using the standard syntax defined here:
http://editorconfig.org/

Meaning you place any standard isort configuration parameters within a .editorconfig file under the ``*.py`` section
and they will be honored.

For a full list of isort settings and their meanings `take a look at the isort wiki <https://github.com/timothycrosley/isort/wiki/isort-Settings>`_.

Multi line output modes
=======================

You will notice above the "multi_line_output" setting. This setting defines how from imports wrap when they extend
past the line_length limit and has 6 possible settings:

**0 - Grid**

.. code-block:: python

    from third_party import (lib1, lib2, lib3,
                             lib4, lib5, ...)

**1 - Vertical**

.. code-block:: python

    from third_party import (lib1,
                             lib2,
                             lib3
                             lib4,
                             lib5,
                             ...)

**2 - Hanging Indent**

.. code-block:: python

    from third_party import \
        lib1, lib2, lib3, \
        lib4, lib5, lib6

**3 - Vertical Hanging Indent**

.. code-block:: python

    from third_party import (
        lib1,
        lib2,
        lib3,
        lib4,
    )

**4 - Hanging Grid**

.. code-block:: python

    from third_party import (
        lib1, lib2, lib3, lib4,
        lib5, ...)

**5 - Hanging Grid Grouped**

.. code-block:: python

    from third_party import (
        lib1, lib2, lib3, lib4,
        lib5, ...
    )

**6 - NOQA**

.. code-block:: python

    from third_party import lib1, lib2, lib3, ...  # NOQA

Alternatively, you can set ``force_single_line`` to ``True`` (``-sl`` on the command line) and every import will appear on its
own line:

.. code-block:: python

    from third_party import lib1
    from third_party import lib2
    from third_party import lib3
    ...

Note: to change the how constant indents appear - simply change the indent property with the following accepted formats:
*   Number of spaces you would like. For example: 4 would cause standard 4 space indentation.
*   Tab
*   A verbatim string with quotes around it.

For example:

.. code-block:: python

    "    "

is equivalent to 4.

For the import styles that use parentheses, you can control whether or not to
include a trailing comma after the last import with the ``include_trailing_comma``
option (defaults to ``False``).

Intelligently Balanced Multi-line Imports
=========================================

As of isort 3.1.0 support for balanced multi-line imports has been added.
With this enabled isort will dynamically change the import length to the one that produces the most balanced grid,
while staying below the maximum import length defined.

Example:

.. code-block:: python

    from __future__ import (absolute_import, division,
                            print_function, unicode_literals)

Will be produced instead of:

.. code-block:: python

    from __future__ import (absolute_import, division, print_function,
                            unicode_literals)

To enable this set ``balanced_wrapping`` to ``True`` in your config or pass the ``-e`` option into the command line utility.

Custom Sections and Ordering
============================

You can change the section order with ``sections`` option from the default of:

.. code-block:: ini

    FUTURE,STDLIB,THIRDPARTY,FIRSTPARTY,LOCALFOLDER

to your preference:

.. code-block:: ini

    sections=FUTURE,STDLIB,FIRSTPARTY,THIRDPARTY,LOCALFOLDER

You also can define your own sections and their order.

Example:

.. code-block:: ini

    known_django=django
    known_pandas=pandas,numpy
    sections=FUTURE,STDLIB,DJANGO,THIRDPARTY,PANDAS,FIRSTPARTY,LOCALFOLDER

would create two new sections with the specified known modules.

The ``no_lines_before`` option will prevent the listed sections from being split from the previous section by an empty line.

Example:

.. code-block:: ini

   sections=FUTURE,STDLIB,THIRDPARTY,FIRSTPARTY,LOCALFOLDER
   no_lines_before=LOCALFOLDER

would produce a section with both FIRSTPARTY and LOCALFOLDER modules combined.

Auto-comment import sections
============================

Some projects prefer to have import sections uniquely titled to aid in identifying the sections quickly
when visually scanning. isort can automate this as well. To do this simply set the ``import_heading_{section_name}``
setting for each section you wish to have auto commented - to the desired comment.

For Example:

.. code-block:: ini

    import_heading_stdlib=Standard Library
    import_heading_firstparty=My Stuff

Would lead to output looking like the following:

.. code-block:: python

    # Standard Library
    import os
    import sys

    import django.settings

    # My Stuff
    import myproject.test

Ordering by import length
=========================

isort also makes it easy to sort your imports by length, simply by setting the ``length_sort`` option to ``True``.
This will result in the following output style:

.. code-block:: python

    from evn.util import (
        Pool,
        Dict,
        Options,
        Constant,
        DecayDict,
        UnexpectedCodePath,
    )

Skip processing of imports (outside of configuration)
=====================================================

To make isort ignore a single import simply add a comment at the end of the import line containing the text ``isort:skip``:

.. code-block:: python

    import module  # isort:skip

or:

.. code-block:: python

    from xyz import (abc,  # isort:skip
                     yo,
                     hey)

To make isort skip an entire file simply add ``isort:skip_file`` to the module's doc string:

.. code-block:: python

    """ my_module.py
        Best module ever

       isort:skip_file
    """

    import b
    import a

Adding an import to multiple files
==================================

isort makes it easy to add an import statement across multiple files, while being assured it's correctly placed.

From the command line:

.. code-block:: bash

    isort -a "from __future__ import print_function" *.py

from within Kate:

.. code-block::

    ctrl+]

or:

.. code-block::

    menu > Python > Add Import

Removing an import from multiple files
======================================

isort also makes it easy to remove an import from multiple files, without having to be concerned with how it was originally
formatted.

From the command line:

.. code-block:: bash

    isort -r "os.system" *.py

from within Kate:

.. code-block::

    ctrl+shift+]

or:

.. code-block::

    menu > Python > Remove Import

Using isort to verify code
==========================

The ``--check-only`` option
---------------------------

isort can also be used to used to verify that code is correctly formatted by running it with ``-c``.
Any files that contain incorrectly sorted and/or formatted imports will be outputted to ``stderr``.

.. code-block:: bash

    isort **/*.py -c -vb

    SUCCESS: /home/timothy/Projects/Open_Source/isort/isort_kate_plugin.py Everything Looks Good!
    ERROR: /home/timothy/Projects/Open_Source/isort/isort/isort.py Imports are incorrectly sorted.

One great place this can be used is with a pre-commit git hook, such as this one by @acdha:

https://gist.github.com/acdha/8717683

This can help to ensure a certain level of code quality throughout a project.


Git hook
--------

isort provides a hook function that can be integrated into your Git pre-commit script to check
Python code before committing.

To cause the commit to fail if there are isort errors (strict mode), include the following in
``.git/hooks/pre-commit``:

.. code-block:: python

    #!/usr/bin/env python
    import sys
    from isort.hooks import git_hook

    sys.exit(git_hook(strict=True))

If you just want to display warnings, but allow the commit to happen anyway, call ``git_hook`` without
the `strict` parameter.

Setuptools integration
----------------------

Upon installation, isort enables a ``setuptools`` command that checks Python files
declared by your project.

Running ``python setup.py isort`` on the command line will check the files
listed in your ``py_modules`` and ``packages``.  If any warning is found,
the command will exit with an error code:

.. code-block:: bash

    $ python setup.py isort

Also, to allow users to be able to use the command without having to install
isort themselves, add isort to the setup_requires of your ``setup()`` like so:

.. code-block:: python

    setup(
        name="project",
        packages=["project"],

        setup_requires=[
            "isort"
        ]
    )


Why isort?
==========

isort simply stands for import sort. It was originally called "sortImports" however I got tired of typing the extra
characters and came to the realization camelCase is not pythonic.

I wrote isort because in an organization I used to work in the manager came in one day and decided all code must
have alphabetically sorted imports. The code base was huge - and he meant for us to do it by hand. However, being a
programmer - I'm too lazy to spend 8 hours mindlessly performing a function, but not too lazy to spend 16
hours automating it. I was given permission to open source sortImports and here we are :)

--------------------------------------------

Thanks and I hope you find isort useful!

~Timothy Crosley