The full docs: https://docs.python.org/3/library/statistics.html
It is a useful library for quick explorations in the terminal. Fire an iPython shell, gather some data in a list, e.g. k, and then:
In [8]: import statistics
In [9]: statistics.mean(k)
Out[9]: 354.2944444444444
In [10]: statistics.stdev(k)
Out[10]: 29.47088274648779
Profit!