Why are there redundant ways to import in Python?

Question

Unless I'm mistaken, these two lines do exactly the same thing:

import theano.tensor as T

from theano import tensor as T

Is there any reason why there are redundant ways to import in Python?

Answer 1

The statement

import theano.tensor

only works if theano.tensor is a module itself. This is what permits both your examples to work.

Consider sys.argv, which is not a module. The following works:

from sys import argv

which imports argv into the global namespace, but the import form does not:

>>> import sys.argv
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: No module named argv