How to properly use python modules

Question

I created a test file called test.py (contained a class named test) and saved it into documents(Mac OS X 10.9.3)

I then attempted to use this file by writing from test import test. However, I got an error telling me that there was no module named test. Please can you shed some light into this issue.

were you in the documents folder when you tried importing it? — Padraic Cunningham, Jul 25 '14 at 10:09
you either have to have modules in your pythonpath or be in the same directory to import them — Padraic Cunningham, Jul 25 '14 at 10:11
can you not just cd to the documents directory and open your shell there? — Padraic Cunningham, Jul 25 '14 at 10:18

score 1 · Answer 1 · edited May 23 '17 at 11:50

The problem is that the Documents folder isn't usually in the PATH or PYTHONPATH, so the interpreter can't see scripts that are stored there (unless Documents happens to be the current working directory).

I can think of two solutions:

Move the file test.py to somewhere within Python's path.

You can find your PYTHONPATH with this script:
```
import os
try:
    user_paths = os.environ['PYTHONPATH'].split(os.pathsep)
except KeyError:
    user_paths = []
```
(From Mark Ransom’s answer to How do I find out my python path using python?)

You can find the system PATH with
```
import sys
print sys.path
```
Both of these return a list of folders. If you put test.py in one of those folders, then it will be seen by the interpreter.

For example, I usually install custom modules at
```
/Library/Python/2.7/site-packages
```
and then I can import them as normal.
Manually append Documents to your path.

You can use sys.path.append to add a directory to the path.

If you only need to use test.py in a handful of scripts, then you can add this code to each script you want to use test.py in:
```
import os
import sys
sys.path.append(os.path.join(os.environ['HOME'], 'Documents'))
from test import test
```

How to properly use python modules

1 Answers1