从不同文件夹导入模块

Question

I have following arrangement of files:

    python
     |--main.py
     |files
        |-----folder1
                |-----a.py,a1.py.....
        |-----folder2
                |-----b.py,b1.py....

I wanted to import my modules a and b.py to main.py. For this I used the following commands in main.py:

    a = 'C:/python/files/folder1'
    sys.path.insert(0, a)
    from files.folder1 import *

However, I am unable to import modules from folder1 ( similarly for folder2). I get an error:

    No module named files.folder1

I cannot use import command as there are many python files in folder1,folder2...so on.

Am I missing something here?

Answer 1

Quick Answer:

Add a file __init__.py (can be blank) to folders files , folder1 and folder2 . Then you got a package files with sub-packages folder1 and folder2 . After this you can import from the main.py like this:

from files.folder1 import *

Answer 2

When I do this in Python 2.7 I use:

import sys
sys.path.append('C:/python/files/folder1')

import a
import a1

UPDATE

Here's a hack I built to import all modules in a directory into a dictionary:

import os
import sys

dir_of_interest = 'C:/python/files/folder1'
modules = {}

sys.path.append(dir_of_interest)
for module in os.listdir(dir_of_interest):
    if '.py' in module and '.pyc' not in module:
        current = module.replace('.py', '')
        modules[current] = __import__(current)

I just built it and it's extremely hacky but it might be more like something you want. So, to access the module you want, instead of saying module_name.thing you would say modules["module_name"].thing

Answer 3

I cannot use import command as there are many python files in folder1,folder2...so on. Am I missing something here?

I believe the part you are missing is the __init__.py file in each of the folders. That file should include an __all__ variable that lists all the submodules that will imported by: from somepackage.subpackage import * .

This is all elegantly explained in the Python Tutorial section on Packages .

Hope this helps :-)

Answer 4

If you add folder1 to the path, that doesn't mean you can import folder1 as a module. It means you can import the files inside folder1. So you could do:

import a
import a1

If you want to have folder1 be a package of which a and a1 are modules, you need to put an __init__.py in folder1 and then do import folder1 . If you further want to be able to do from folder1 import * and have that import a and a1 , you need to put code in your __init__.py that imports a and a1 .

If you have a lot of files in a folder that you want to be able to import in a structured way, you should make that folder into a package.

Answer 5

Looking at the folder structure , what you could do is , Simply

from files.folder1 import a , a1
from files.folder2 import b , b1

and this should help

.

Extras : I recently thought of a problem , of importing pip packages without actually installing them , then what i did was ... i pip installed the package in a virtual environment and copied only folder of the package name

eg. if the package name is qwikidata , then i went to /Lib folder and copied only the qwikidata folder and pasted it in the root of my project , in your case , where the main.py file is and pip uninstalled the package , to avoid the errors

And now i was able to import the package without actually pip installing it since the package was in my root folder of the project

If the project is not so complicated , then it should be fine , but I wouldn't recommend this way of installing packages .

It helps when you want to run your project on some other machine and You dont have an Internet connection .