如何解决“ ImportError：没有名为…的模块”

Question

I have reviewed most of the similar question here. I'm new to python and I'm using Ubuntu 13.10 The project structure is

├── projecttest
│   ├── api.py
│   ├── controller
│   │   ├── controller.py
│   │   ├── controller.pyc
│   │   ├── init_db.py
│   │   ├── __init__.py
│   │   ├── __init__.pyc
│   │   ├── settings.py
│   │   ├── settings.pyc
│   │   └── extra
│   │       ├── extra.py
│   │       ├── extra.pyc
│   │       ├── __init__.py
│   │       └── __init__.pyc
│   ├── __init__.py
│   ├── lib
│   │   └── __init__.py
│   ├── models
│   │   ├── documents.py
│   │   ├── documents.pyc
│   │   └── __init__.py

All the __init__.py files are empty (no hidden characters) and when I'm trying

$ python init_db.py

that has:

from projecttest.models.documents import *

I'm getting:

Traceback (most recent call last):
  File "controllers/init_db.py", line 1, in <module>
    from projecttest.models.documents import *
ImportError: No module named projecttest.models.documents

Answer 1

You need to specify PYTHONPATH environment variable, it augments the default search path for module files.

It helps to think about PYTHONPATH as an absolute path. If you specify it you may import modules within your program relative to PYTHONPATH.

In your case it would be something like the following line:

PYTHONPATH=/<dir>/<folder>/projecttest/ python init_db.py

Then you may import modules without problems like:

from models.documents import *