将所有Python导入文件保存在一个文件中

Question

I have a file and it has lot of imports:

import x
from y import z
and so on .... 

Is there a way to keep all the imports in another file called 'AllImports.py' and be able to do something as:

import AllImports as im

Then be able to use:

im.x
im.z
and so on

I want to do this because my file has about 20 rows of imports, and it's going to increase. Why is it not a good practice?

Answer 1

When you do this:

File a.py :

import x

It imports everything in x ... including the other imports. If x has this defined at the top:

import y

Then you can do this in a :

x.y

Therefore, if you do this in a :

import x as z

You can also then do:

z.y

The difficulty with this is that you are importing a function at the point where it is imported: adding degrees of indirection makes things such as testing, and determining what is actually going on in your file, harder. Good IDEs allow you to collapse import lists, which means the problem you're trying to solve (not having to see a huge list of imports) is more simply solved with a good tool.

I would note, too, that one of the most important things code can be is readable. By forcing yourself to use the im. namespace in front of everything, you are occluding what your code is doing, and preventing you from writing code that is elegant and easy to read and understand.