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pythoncode-analysispylint

Tool to help eliminate wildcard imports


I'm refactoring and eliminating wildcard imports on some fairly monolithic code.

Pylint seems to do a great job of listing all the unused imports that come along with a wildcard import, but what i wish it did was provide a list of used imports so I can quickly replace the wildcard import. Any quick ways of doing this? I'm about to go parse the output of pyLint and do a set.difference() on this and the dir() of the imported module. But I bet there's some tool/procedure I'm not aware of.


Solution

  • NB: pylint does not recommend a set of used imports. When changing this, you have to be aware of other modules importing the code you are modifying, which could use symbols which belong to the namespace of the module you are refactoring only because you have unused imports.

    I recommend the following procedure to refactor from foo import *:

    • in an interactive shell, type:

      import re
      import foo as module # XXX use the correct module name here!
      
      module_name = module.__name__
      import_line = 'from %s import (%%s)' % module_name
      length = len(import_line) - 3
      print import_line % (',\n' + length * ' ').join([a for a in dir(module) 
                                                                     if not re.match('__.*[^_]{2}', a)])
      
    • replace the from foo import * line with the one printed above

    • run pylint, and remove the unused imports flagged by pylint
    • run pylint again on the whole code based, looking for imports of non existing sympols
    • run your unit tests

    repeat with from bar import *