Can Python modules have properties the same way that objects can?

Question

With python properties, I can make it such that

x.y

calls a function rather than just returning a value.

Is there a way to do this with modules?

I have a case where I want m.y to call a function rather than just returning the value stored there.

C

Answer 1

Only instances of new-style classes can have properties. You can make Python believe such an instance is a module by stashing it in sys.modules[thename] = theinstance. So, for example, your m.py module file could be:

import sys
class _M(object):
  def __init__(self):
    self.c = 0
  def afunction(self):
    self.c += 1
    return self.c
  y = property(afunction)
sys.modules[__name__] = _M()

Edited: removed an implicit dependency on globals (had nothing to do with the point of the example but did confuse things by making the original code fail!).

Answer 2

I would do this in order to properly inherit all the attributes of a module, and be correctly identified by isinstance()

import types

class MyModule(types.ModuleType):
    @property
    def y(self):
        return 5


>>> a=MyModule("test")
>>> a
<module 'test' (built-in)>
>>> a.y
5

And then you can insert this into sys.modules