Calculating variance is easy using Python. Before diving into the Python code, I’ll first explain what variance is and how you can calculate it.

We'll calculate the historical monthly variance of the S&P 500 Total Return index over a five-year period from August 2010 through July 2015 -- that's 60 observations (5 years x 12 months).

Calculating variance is easy using Python. Before diving into the Python code, I’ll first explain what variance is and how you can calculate it. By the end of this tutorial you’ll have a ...