This extension is targeted at production databases. Therefore certain restrictions must be assumed about the production environment vs other experimental environments.
We're using pip and virtualenv to generate a suitable isolated environment for python code that has all the dependencies
Every dependency should be:
- Added to the setup.py file
- Installed through it
- Tested, when they have a test suite.
- Fixed in the requirements.txt
At present we use Python version 2.7.3

Sample session with virtualenv

Create and use a virtual env

# Create the virtual environment for python
$ virtualenv myenv

# Activate the virtualenv
$ source myenv/bin/activate

# Install all the requirements
# expect this to take a while, as it will trigger a few compilations
(myenv) $ pip install -r requirements.txt

# Add a new pip to the party
(myenv) $ pip install pandas

Test the libraries with that virtual env

Test numpy library dependency:

import numpy
numpy.test('full')

output:

======================================================================
ERROR: test_multiarray.TestNewBufferProtocol.test_relaxed_strides
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/ubuntu/www/crankshaft/src/py/dev2/lib/python2.7/site-packages/nose/case.py", line 197, in runTest
    self.test(*self.arg)
  File "/home/ubuntu/www/crankshaft/src/py/dev2/lib/python2.7/site-packages/numpy/core/tests/test_multiarray.py", line 5366, in test_relaxed_strides
    fd.write(c.data)
TypeError: 'buffer' does not have the buffer interface

----------------------------------------------------------------------
Ran 6153 tests in 84.561s

FAILED (KNOWNFAIL=3, SKIP=5, errors=1)
Out[2]: <nose.result.TextTestResult run=6153 errors=1 failures=0>

NOTE: this is expected to fail with Python 2.7.3, which is the version embedded in our postgresql installation

Run scipy tests

import scipy
scipy.test('full')

Output:

Ran 21562 tests in 321.610s

OK (KNOWNFAIL=130, SKIP=1840)
Out[2]: <nose.result.TextTestResult run=21562 errors=0 failures=0>

Ok, this looks good...

Testing pysal

See [http://pysal.readthedocs.org/en/latest/developers/testing.html]

import pysal
import nose
nose.runmodule('pysal')

Ran 537 tests in 42.182s

FAILED (errors=48, failures=17)
An exception has occurred, use %tb to see the full traceback.

This doesn't look good... Taking a deeper look at the failures, many have the IOError: [Errno 2] No such file or directory: 'streets.shp'

In the source code, there's the following config that seems to be missing in the pip package. By copying it to lib/python2.7/site-packages within the environment, it goes down to 17 failures.

The remaining failures don't look good. I see two types: precision calculation errors and arrays/matrices missing 1 element when comparing... TODO: FIX this