module alias in import statement

[Terry Reedy]

On 4/4/2016 11:31 AM, ast wrote:
> hello
>
>>>> import tkinter as tk
>>>> import tk.ttk as ttk
>
> Traceback (most recent call last):
>   File "<pyshell#3>", line 1, in <module>
>     import tk.ttk as ttk
> ImportError: No module named 'tk'
>
>
> of course
>
>>>> import tkinter.ttk as ttk
>
> works
>
> Strange, isn't it ?

Nope. As other said, 'import tkinter as tk' imports a module named 
'tkinter' and *in the importing modules, and only in the importing 
module*, binds the module to 'tk'.  It also caches the module in 
sys.modules under its real name, 'tkinter'.

 >>> import tkinter as tk
 >>> import sys
 >>> 'tkinter' in sys.modules
True
 >>> 'tk' in sys.modules
False

'import tk.ttk' looks for 'tk' in sys.modules, does not find it, looks 
for a module named 'tk' on disk, does not find it, and says so.

-- 
Terry Jan Reedy