I have some stock data based on daily close values. I need to be able to insert these values into a python list and get a median for the last 30 closes. Is there a python library that does this?
Have you considered pandas? It is based on numpy and can automatically associate timestamps with your data, and discards any unknown dates as long as you fill it with numpy.nan. It also offers some rather powerful graphing via matplotlib.
Basically it was designed for financial analysis in python.