Question

Is this a good practice in Python (from Active State Recipes — Public Decorator)?

import sys

def public(f):
  """Use a decorator to avoid retyping function/class names.

  * Based on an idea by Duncan Booth:
  http://groups.google.com/group/comp.lang.python/msg/11cbb03e09611b8a
  * Improved via a suggestion by Dave Angel:
  http://groups.google.com/group/comp.lang.python/msg/3d400fb22d8a42e1
  """
  all = sys.modules[f.__module__].__dict__.setdefault('__all__', [])
  if f.__name__ not in all:  # Prevent duplicates if run from an IDE.
      all.append(f.__name__)
  return f

public(public)  # Emulate decorating ourself

The general idea would be to define a decorator that takes a function or class
and adds its name to the __all__ of the current module.

Answer 1

Yes, it’s a good practice. This decorator allows you to state your intentions right at function or class definition, rather than directly afterwards. That makes your code more readable.

@public 
def foo():
    pass 

@public 
class bar():
    pass

class helper(): # not part of the modules public interface! 
    pass

Note: helper is still accessible to a user of the module by modulename.helper. It’s just not imported with from modulename import *.