Python导入：在一个文件中导入多个模块

Question

I have many frequently used modules such as os, cv2, numpy, ... Every time I need to import them at the beginning of each python file. Now I want to write the import code into one file named all_import.py , and for each python file only import all_import to import all the modules I need.

Is that possible to do that?

Answer 1

Yes, this is possible (but really should not be done). Just set up your files like so:

b.py

import numpy
import scipy

a.py

from b import *

And then use whatever you imported in b.py

Answer 2

It is not recommended to do such thing but theoretically it is doable.

all_import.py :

import os
import cv2
import numpy

__all__ = ['os', 'cv2', 'numpy']

other_script.py :

import all_import as ai

# use `os`
ai.os.system('echo "Hello!"')

Comparing to @chrisz's answer, this one doesn't violate any PEP8 format.

Answer 3

create a folder as python package

my_fodler

inside it, create an __init__.py file, where you add all your imports.

import os
import subprocess

go back to the same path as my_folder and create your file, and there you call your package like:

from my_folder import *

Here is how it would look like:

----|> my_folder

----|----> __init__.py

----|> your_file.py