Is there a conflict of libraries here?

[Mats Wichmann]

On 11/6/20 3:05 PM, Steve wrote:
> "Right, because the name "datetime" points to the class datetime in the
> module datetime.
> The class, unlike the module, has no "datetime" attribute."
> 
>   
> 
> Ok, how do I unpoint/repoint a "datetime" to let the two locations work?
> 
>   
> 
> "Apologies if you already knew this.  I wasn't sure."
> 
>   
> 
> Absolutely did not know any of this.
> Libraries are a slow learning process for me....
> 

The Python import command does some stuff behind the scenes, but from 
the programmer viewpoint, you're just manipulating names in namespaces - 
making a mapping of a name to the relevant object.


import boo

gives you a name 'boo' in the relevant namespace, which refers to the 
module object made for boo when it was imported (that's some of the 
behind the scenes stuff).

A quick interactive sample showing this in action:

 >>> globals()
{'__name__': '__main__', '__doc__': None, '__package__': None, 
'__loader__': <class '_frozen_importlib.BuiltinImporter'>, '__spec__': 
None, '__annotations__': {}, '__builtins__': <module 'builtins' (built-in)>}
 >>> import sys
 >>> globals()
{'__name__': '__main__', '__doc__': None, '__package__': None, 
'__loader__': <class '_frozen_importlib.BuiltinImporter'>, '__spec__': 
None, '__annotations__': {}, '__builtins__': <module 'builtins' 
(built-in)>, 'sys': <module 'sys' (built-in)>}

here's the case you are running into:

 >>> import datetime
 >>> globals()
{'__name__': '__main__', '__doc__': None, '__package__': None, 
'__loader__': <class '_frozen_importlib.BuiltinImporter'>, '__spec__': 
None, '__annotations__': {}, '__builtins__': <module 'builtins' 
(built-in)>, 'datetime': <module 'datetime' from 
'/usr/lib64/python3.8/datetime.py'>}
 >>> from datetime import datetime
 >>> globals()
{'__name__': '__main__', '__doc__': None, '__package__': None, 
'__loader__': <class '_frozen_importlib.BuiltinImporter'>, '__spec__': 
None, '__annotations__': {}, '__builtins__': <module 'builtins' 
(built-in)>, 'datetime': <class 'datetime.datetime'>}


If you want to import the datetime class and still have the full 
datetime module available, you can for example import as a different 
name - here's a sample of that:

 >>> import datetime as dt
 >>> from datetime import datetime
 >>> globals()
{'__name__': '__main__', '__doc__': None, '__package__': None, 
'__loader__': <class '_frozen_importlib.BuiltinImporter'>, '__spec__': 
None, '__annotations__': {}, '__builtins__': <module 'builtins' 
(built-in)>, 'dt': <module 'datetime' from 
'/usr/lib64/python3.8/datetime.py'>, 'datetime': <class 
'datetime.datetime'>}

Does this make it clearer?