Installing networkx Python package in QGIS

Question

How to install and how to compile networkx python on QGIS?

I always get an error that no module named networkx in the console of QGIS.

I copied the file networkx in C:\Program Files\Quantum GIS Lisboa\apps\Python27\Lib\site-packages and there are not change.

Answer 1

I copied the file networkx

It is not a simple file, it is a folder with many files. You must place the entire unzipped networkx folder in C:\Program Files\Quantum GIS Lisboa\apps\Python27\Lib\site-packages (because it is a simple module)

In general, to use a Python module, you must first install it:

python setup.py install

As on Windows, QGIS uses its own version of Python (not in the Windows's registry), without a Python shell, you can:

1. use the bootstrapped installer for setuptools of Nathan's QGIS Blog, which will install directly the module into a folder rather than looking in the registry
2. download the networkx version of Christoph Gohlke at Unofficial Windows Binaries for Python Extension Packages, unzip it (it is a .exe file but you can directly unzip it) and place the resulting folder in C:\Program Files\Quantum GIS Lisboa\apps\Python27\Lib\site-packages.

After that, in the Python console of QGIS:

import networkx
networkx.__file__
'C:\Program Files\Quantum GIS Lisboa\apps\Python27\Lib\site-packages\networkx\__init__.pyc'

or

'C:\Program Files\Quantum GIS Lisboa\apps\Python27\Lib\site-packages\networkx-1.7-py2.7.egg\networkx\__init__.pyc'

depending on how you installed the module

Answer 2

The easiest way to install networkx python module to run it from QGIS is to use OSGeo4W installer. It will handle all the dependencies that networkx rely on.

Download OSGeo4W Network installer from QGIS download page, then right-click the EXE file and select Run as Administrator, select Advance install and follow the steps until you find the following window:

In the Search box write networkx and you will have two versions located under Libs: one for python 2 and the other for python 3. Choose networkx for python 2 because this what is currently used in QGIS 2.X.X and click on Next to install. In the image above it is written Keep because it is already installed, but for the first time installation you have to click Install.

When the installation finishes successfully, you can import networkx module directly from inside QGIS Python Console, and it will not give an import error.