[Python] Importing correctly with pytest

I just got set up to use pytest with Python 2.6. It has worked well so far with the exception of handling "import" statements: I can't seem to get pytest to respond to imports in the same way that my program does.

My directory structure is as follows:

src/
main.py
util.py
test/
test_util.py
geom/
vector.py
region.py
test/
test_vector.py
test_region.py


To run, I call python main.py from src/.

In main.py, I import both vector and region with

from geom.region import Region
from geom.vector import Vector


In vector.py, I import region with

from geom.region import Region


These all work fine when I run the code in a standard run. However, when I call "py.test" from src/, it consistently exits with import errors.

Some Problems and My Solution Attempts


My first problem was that, when running "test/test_foo.py", py.test could not "import foo.py" directly. I solved this by using the "imp" tool. In "test_util.py":

import imp
util = imp.load_source("util", "util.py")


This works great for many files. It also seems to imply that when pytest is running "path/test/test_foo.py" to test "path/foo.py", it is based in the directory "path".

However, this fails for "test_vector.py". Pytest can find and import the vector module, but it cannot locate any of vector's imports. The following imports (from "vector.py") both fail when using pytest:

from geom.region import *
from region import *


These both give errors of the form

ImportError: No module named [geom.region / region]


I don't know what to do next to solve this problem; my understanding of imports in Python is limited.

What is the proper way to handle imports when using pytest?

Edit: Extremely Hacky Solution


In vector.py, I changed the import statement from

from geom.region import Region


to simply

from region import Region


This makes the import relative to the directory of "vector.py".

Next, in "test/test_vector.py", I add the directory of "vector.py" to the path as follows:

import sys, os
sys.path.append(os.path.realpath(os.path.dirname(__file__)+"/.."))


This enables Python to find "../region.py" from "geom/test/test_vector.py".

This works, but it seems extremely problematic because I am adding a ton of new directories to the path. What I'm looking for is either

1) An import strategy that is compatible with pytest, or

2) An option in pytest that makes it compatible with my import strategy

So I am leaving this question open for answers of these kinds.

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