从另一个包Python导入类

Question

My source code directory (named my_dir ) is organized as follow:

my_dir
|
|-- pkg_1
|    |
|    |-- module_1.py
|    |-- module_2.py
|
|-- src.py

In module_1.py , I import module_2.py by

import module_2

But when I import module_1 in src.py by

import module_1

An error is raised as the statement import module_2 in module_1.py acts as if my working directory is pkg_1 instead of my_dir .

How can it fix this ?

Answer 1

in module_1.py import it as from . import module_2 from . import module_2 and in src.py import module_1 as from pkg_1 import module_1

Answer 2

This is the cause of the misunderstanding:

An error is raised as the statement import module_2 in module_1.py acts as if my working directory is pkg_1 instead of my_dir .

First of all, when you import a package, the code in that package does not execute in a different working directory.

The second mistake is that the working directory is not relevant at all, even if it did change.

Python code is organised into packages and modules. The interpreter searches for packages and modules within the python path.

In the structure shown, my_dir will be in python path if you run python src.py . Then pkg_1 is a package whereas module_1 and module_2 are modules. The easiest way to import module_2 is to use an absolute import:

import pkg_1.module_2

Alternatively, from within another module in pkg_1 you can use a relative import :

from . import module_2

Answer 3

Try this:

#!/usr/bin/env python
# -*- coding: utf-8 -*-

import os, sys;

# get path to this file.
path_this_file = os.path.dirname(os.path.abspath(__file__));
# add path to import files.
sys.path.insert(0, path_this_file + "/pkg_1");

import module_1, module_2;