networkx/networkx — pull request #774 by yaph (2012-10-05 10:25:01+00:00)
Title: Set default value for alpha channel in viz:color elements

When trying to read an gexf file created with Gephi, I got the following error.

File "/usr/local/lib/python2.7/dist-packages/networkx/readwrite/gexf.py", line 693, in add_viz
'a':float(color.get('a')),
TypeError: float() argument must be a string or a number

The alpha channel value was not set by Gephi and according to the [gexf 1.2 schema](http://gexf.net/1.2draft/viz.xsd) it is not required. Thus I suggest setting the default to 100.