While it's been quiet on this blog, but behind the scenes I have been very busy trying to build an interactive spread scanner. To make one, a list of ingredients is needed:
gui toolkit: pyqt -check.
data aquisition: ibpy & tradingWithPython.lib.yahooData - check.
data container: pandas & sqlite - check.
plotting library: matplotlib - ehm... No.
After tinkering with matplotlib in pyqt for several days I must admit its use in interactive applications is far from optimal. Slow, difficult to integrate and little interactivity. PyQwt proven to work a little better, but it had its own quirks, a little bit too low-level for me.
But as it often happens with Python, somebody, somewhere has already written a kick-ass toolkit that is just perfect for the job. And it looks like guiqwt is just it. Interactive charts are just a couple of code lines away now, take a look at an example here: Creating curve dialog . For this I used guiqwt example code with some minor tweaks.
And of course a pretty picture of the result:
...If only I knew how to set dates on the x-axis....