Importanize (import organize)

Utility for organizing Python imports using PEP8 or custom rules

• Free software: MIT license
• GitHub: https://github.com/miki725/importanize

Installing

You can install importanize using pip:

$ pip install importanize

Why?

I think imports are important in Python. I also think PEP8 is awesome (if you disagree, read some PHP) and there are many tools to help developers reformat code to match PEP8. There are however fewer tools for organizing imports either by following PEP8 or custom rules. There is isort (which unfortunately I found out about after writing this lib) however it seems to do lots of magic to determine which packages are 3rd party, local packages, etc. I wanted the imports configuration to be simple and explicit. This is where importanize comes in. It allows to organize Python imports using PEP8 or your custom rules. Read on for more information.

Using

Using importanize is super easy. Just run:

$ importanize file_to_organize.py

That will re-format all imports in the given file. As part of the default configuration, importanize will try it's best to organize imports to follow PEP8 however that is a rather challenging task, since it is difficult to determine all import groups as suggested by PEP8:

1. standard library imports
2. related third party imports
3. local application/library specific imports

To help importanize distinguish between different import groups in most cases it would be recommended to use custom config file:

$ importanize file_to_organize.py config.json

Config file is simply a json file like this:

{
    "formatter": "grouped",
    "groups": [
        {
            "type": "stdlib"
        },
        {
            "type": "sitepackages"
        },
        {
            "type": "remainder"
        },
        {
            "type": "packages",
            "packages": [
                "my_favorite_package"
            ]
        },
        {
            "type": "local"
        }
    ]
}

Default config looks something like:

{
    "groups": [
        {
            "type": "stdlib"
        },
        {
            "type": "sitepackages"
        },
        {
            "type": "remainder"
        },
        {
            "type": "local"
        }
    ]
}

Currently the only required key is "groups" which must be an array of group definitions. importanize will use these group definitions to organize imports and will output import groups in the same order as defined in the config file. These are the supported group types:

• stdlib - standard library imports including __future__

• sitepackages - imports coming from the site-packages directory

• local - local imports which start with ".". for example from .foo import bar

• packages - if this group is specified, additional key packages is required within import group definition which should list all Python packages (root level) which should be included in that group:

  {
      "type": "packages",
      "packages": ["foo", "bar"]
  }
  

• remaining - all remaining imports which did not satisfy requirements of all other groups will go to this group.

You can use the config file by specifying it in the importanize command as shown above however you can also create an .importanizerc file and commit that to your repository. As a matter of fact, you can see the .importanizerc config file used for the importanize repository itself. Additionally multiple configurations are supported within a single repository via sub-configurations. Simply place .importanizerc within a sub-folder and all imports will be reconfigured under that folder.

You can also choose the formatter used to organize long multiline imports. Currently, there are two formatters available:

• grouped (default)
• inline-grouped

It can be set using the formatter config value, or the formatter option, for example:

$ importanize --formatter=inline-group --print tests/test_data/input.txt

Finally, you can see all other available importanize cli options:

$ importanize --help

Not all configurations can be provided via cli. Additional available configurations in configuration file:

• length - line length after which the formatter will split imports

• exclude - list of glob patterns of files which should be excluded from organizing. For example:

  "exclude": [
      "path/to/file",
      "path/to/files/ignore_*.py"
  ]
  

• after_imports_new_lines - number of lines to be included after imports

• add_imports - list of imports to add to every file. For example:

  "add_imports": [
      "from __future__ import absolute_import, print_function, unicode_literals"
  ]
  

It integrates with pre-commit. You can use the following config

repos:
- repo: https://github.com/miki725/importanize/
  rev: 'master'
  hooks:
  - id: importanize
    args: [--verbose]

Example

Here is a before and after using the default formatter(on hypothetical file):

Before

from __future__ import unicode_literals, print_function
import os.path as ospath
import datetime
from package.subpackage.module.submodule import CONSTANT, Klass, foo, bar, rainbows
from .module import foo, bar
from ..othermodule import rainbows

After

from __future__ import print_function, unicode_literals
import datetime
from os import path as ospath

from package.subpackage.module.submodule import (
    CONSTANT,
    Klass,
    bar,
    foo,
    rainbows,
)

from ..othermodule import rainbows
from .module import bar, foo

Here is what importanize did:

• alphabetical sort, even inside import line (look at __future__)
• normalized import .. as .. into from .. import .. as ..
• broke long import (>80 chars) which has more than one import into multiple lines
• reordered some imports (e.g. local imports .. should be before .)

Testing

To run the tests you need to install testing requirements first:

$ make install

Then to run tests, you can use nosetests or simply use Makefile command:

$ nosetests -sv
# or
$ make test