I use a variety of basic editors (gedit) to DAWN. *Terrible plug warning* DAWN (www.dawnsci.org) is an eclipse RCP based client, which includes PyDev (another very good python editor) and IPython. As well as this there's a range of tools for plotting and visualising graphical data. You can also use Jython and we have developed a Jython clone of the numpy library with many more bells & whistles (which are also accessible with C Python). Here endeth the plug.
The advantage of DAWN is that it has the data visualisation tools. The disadvantage is that, as an eclipse client, it's pretty heavyweight.
I'm Michael. I work at Diamond Light Source as a post-doc on beamline I15-1 and was previously working in the data analysis group. We're looking at how we might use the CSD python API to check data that comes off the beamline against known structures in the CSD and whether it can be integrated with our existing software.