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removestar

Tool to automatically replace 'import *' in Python files with explicit imports

removestar

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Tool to automatically replace import * imports with explicit imports

Requires pyflakes.

Current limitations:

For files within the same module, removestar determines missing imported names statically. For external library imports, including imports of standard library modules, it dynamically imports the module to determine the names. This can be disabled with the --no-dynamic-importing flag.

See the issue tracker. Pull requests are welcome.

Installation

pip install removestar

or if you use conda

conda install -c conda-forge removestar

Usage

$ removestar file.py # Shows diff but does not edit file.py

$ removestar -i file.py # Edits file.py in-place

$ removestar -i module/ # Modifies every Python file in module/ recursively

Why is import * so bad?

Doing from module import * is generally frowned upon in Python. It is considered acceptable when working interactively at a python prompt, or in __init__.py files (removestar skips __init__.py files by default).

Some reasons why import * is bad:

Here are some official Python references stating not to use import * in files:

Unfortunately, if you come across a file in the wild that uses import *, it can be hard to fix it, because you need to find every name in the file that is imported from the *. Removestar makes this easy by finding which names come from * imports and replacing the import lines in the file automatically.

Example

Suppose you have a module mymod like

mymod/
  | __init__.py
  | a.py
  | b.py

With

# mymod/a.py
from .b import *

def func(x):
    return x + y
# mymod/b.py
x = 1
y = 2

Then removestar works like:

$ removestar mymod/

--- original/mymod/a.py
+++ fixed/mymod/a.py
@@ -1,5 +1,5 @@
 # mymod/a.py
-from .b import *
+from .b import y

 def func(x):
     return x + y

This does not edit a.py by default. The -i flag causes it to edit a.py in-place:

$ removestar -i mymod/
$ cat mymod/a.py
# mymod/a.py
from .b import y

def func(x):
    return x + y

Command line options

$ removestar --help
usage: removestar [-h] [-i] [--version] [--no-skip-init]
                  [--no-dynamic-importing] [-v] [-q]
                  [--max-line-length MAX_LINE_LENGTH]
                  PATH [PATH ...]

Tool to automatically replace "import *" imports with explicit imports

Requires pyflakes.

Usage:

$ removestar file.py # Shows diff but does not edit file.py

$ removestar -i file.py # Edits file.py in-place

$ removestar -i module/ # Modifies every Python file in module/ recursively

positional arguments:
  PATH                  Files or directories to fix

optional arguments:
  -h, --help            show this help message and exit
  -i, --in-place        Edit the files in-place. (default: False)
  --version             Show removestar version number and exit.
  --no-skip-init        Don't skip __init__.py files (they are skipped by
                        default) (default: True)
  --no-dynamic-importing
                        Don't dynamically import modules to determine the list
                        of names. This is required for star imports from
                        external modules and modules in the standard library.
                        (default: True)
  -v, --verbose         Print information about every imported name that is
                        replaced. (default: False)
  -q, --quiet           Don't print any warning messages. (default: False)
  --max-line-length MAX_LINE_LENGTH
                        The maximum line length for replaced imports before
                        they are wrapped. Set to 0 to disable line wrapping.
                        (default: 100)

Changelog

See the CHANGELOG file.

License

MIT