ng-describe | Convenient BDD specs for Angular | Functional Testing library

I have a list of tuples [(val1, freq1), (val2, freq2) .... (valn, freqn)]. I need to get measures of central tendencies (mean, median ) and measures of deviation (variance , mean) for the above data.I would also like to plot a boxplot for the values.

I see that numpy arrays have direct methods for getting mean / median and standard deviation (or variance) from list of values.

Does numpy (or any other well-known library) have a direct means to operate on such a frequency distribution table ?

Also What is the best way to programtically expand the above list of tuples to one list ? (e.g if freq dist is [(1,3) , (50,2)], best way to get a list [1,1,1,50,50] to use np.mean([1,1,1,50,50]))

I see a custom function here, but I would like to use a standard implementation if possible