You should invest your time in python 3... ArcGIS Pro uses python 3.5/6 and there is a fundamental statistics package now built into python.
9.7. statistics — Mathematical statistics functions — Python 3.7.0 documentation
import sys
sys.version
'3.6.6 |Anaconda, Inc.| (default, Jun 28 2018, 11:27:44) [MSC v.1900 64 bit (AMD64)]'
import statistics
dir(statistics)
['Decimal', 'Fraction', 'StatisticsError', '__all__', '__builtins__', '__cached__', '__doc__', '__file__', '__loader__', '__name__', '__package__', '__spec__', '_coerce', '_convert', '_counts', '_exact_ratio', '_fail_neg', '_find_lteq', '_find_rteq', '_isfinite', '_ss', '_sum', 'bisect_left', 'bisect_right', 'chain', 'collections', 'decimal', 'groupby', 'harmonic_mean', 'math', 'mean', 'median', 'median_grouped', 'median_high', 'median_low', 'mode', 'numbers', 'pstdev', 'pvariance', 'stdev', 'variance']