Comment 2 for bug 1285611

We are waiting for version 1.9 package to be included, meanwhile a workaround can be done:

do it in two phases:
install python-networkx (if not done already):
sudo apt-get install python-networkx
then you will need to move python-networkx doc:
sudo mv /usr/share/doc/python-networkx /usr/share/doc/python2.7-networkx
so the documentation for python-networkx will be available from /usr/share/doc/python2.7-networkx
don't forget to manually remove this directory if you remove/purge package

then:
sudo apt-get download python3-networkx
sudo dpkg -i --force-download python3-networkx

then the documentation for python3-networkx, will be splitted in two parts:
/usr/share/doc/python3-networkx and /usr/share/doc/python-networkx

Not very nice but it allows you to install both of them.
If you remove python-networkx, il will remove the python3-networkx, so you may want to copy documention if you want to keep python3-netwokrx documentation
sudo mv /usr/share/doc/python-networkx /usr/share/doc/python3-networkx
if you do so, don't forget to manually remove this directory when removing python3-networkx