The namespace for builtin functions?

[Bengt Richter]

On Sun, 30 Nov 2003 19:00:16 +0100, "Fredrik Lundh" <fredrik at pythonware.com> wrote:

>Blair Hall wrote:
>
>> Can anyone please tell me how to correctly use a built in function
>> when there is a function of the same name in local scope?
>>
>> Here is an example. Suppose the following is in myApply.py:
>>
>> def apply(func,seq):
>>      #
>>      # Code can default to
>>      # built-in definition in some cases:
>>      return __builtins__.apply(func,seq)
>
>the module is named __builtin__, and must be imported before
>it can be used.
>
>__builtins__ is a CPython implementation detail (it's used to cache
>a reference to the builtin modules, and are initialized on demand).
>
>for more info, see the "Overloading functions from the __builtin__
>module" here:
>
>    http://effbot.org/zone/librarybook-builtin.htm
Weird -- netscape 4.5 claims that document "contains no data"
wget got it though. Maybe time to reboot windows ;-/
>
I think I agree with Francis. Why is __builtins__ set up
in the interactive namespace differently from an imported
module's namespace? To show what he was saying again, I made
and empty module (nothing but an empty line in its source):

 >>> file('empty.py').read()
 '\n'
 >>> import empty
 >>> dir(empty)
 ['__builtins__', '__doc__', '__file__', '__name__']

Ok, now in the interactive namespace:

 >>> __builtins__
 <module '__builtin__' (built-in)>

And in the 'empty' module's namespace:

 >>> `empty.__builtins__`[:60]
 "{'help': Type help() for interactive help, or help(object) f"

(I knew I would be getting the whole dict repr if I just typed empty.__builtins__ ;-)

 >>> type(__builtins__)
 <type 'module'>
 >>> type(empty.__builtins__)
 <type 'dict'>
 >>> __builtins__.__dict__ is empty.__builtins__
 True
 >>>

Seems inconsistent. Why not

    __builtins__ is empty.__builtins__ => True

and hence

    __builtins__.__dict__ is empty.__builtins__.__dict__ => True

(or maybe both __builtins__ bindings could be to the dict, though that would
bypass potential getattr magic that might be needed somewhere?)

Regards,
Bengt Richter