无法从包中导入python模块

Question

My project path is like:

main.py
modules/
     __init__.py
     databaseManager.py
     sync.py
     excel.py

in main.py:

from modules.databaseManger import addExcelToDb, searchInDbAll
from modules.excel import search, showExcelDirContents
from modules.sync import syncExcelAndDB

and for example in database.py :

from modules.excel import showExcelDirContents
from modules.sync import insertExcelNameToSyncDb

but when I run main.py I get this error:

Traceback (most recent call last):
 File "main.py", line 6, in <module>
   from modules.databaseManger import searchIn
ImportError: cannot import name 'searchInDbAll'

and also having error when trying to import a function from each file in modules directory to others.

I need some examples of import ing.

Answer 1

You can append to your path where you put your modules like this:

import sys
sys.path.append('modules/')

or

import sys
sys.path.append('c:/mycode/stuff/modules/')

note those are forward slashes, or you can use double backslashes like \\\\

Then just have your databaseManger.py file in /modules

You'll also need to have a file in the /modules folder named:

__init__.py

Which is just an empty file

Then you should be able to do:

from databaseManger import addExcelToDb, searchInDbAll

Answer 2

This is circular import issue.

Explanation:

You start by triggering import of databaseManager module.

During this databaseManager code starts to import excel .

During excel importing, excel code tries to retrieve function searchInDbAll() from databaseManager . But at that moment this function does not exist - because databaseManager is in process of importing excel and he hasn't started defining any functions.

How to fix:

In modules where circular import conflicts exist, import modules instead of functions. For example, change this:

from modules.excel import showExcelDirContents

to that:

from modules import excel

And of course, you must then change corresponding function calls, from showExcelDirContents() to excel.showExcelDirContents() .

You must do this in your databaseManger , excel and sync modules. With this fix, I actually could run your code.

And yeah, remove appends to sys.path, that is wrong