List of Compounding Months - Python

Question

I'm not sure if compounding is the right word for what I'm asking; but, is it possible to make a python list of compounding/cumulative months? For example, [Jan, Jan+Feb, Jan+Feb+Mar]. I want to use this to help me show customer growth from month to month. I've looked online, but can't find any examples of this. Is it possible?

DanPatterson_Retired · Answer

Good point... but If you are still using ArcMap (python 2.7)  The numpy version is available for both 2.7 and 3.6

bixb0012 · Answer

I am not sure which version of Python you are using (2.x or 3.x), but accumulate was introduced in Python 3.2 if you are using Python 3: >>> from itertools import accumulate >>> l = [3, 3, 1, 3, 3, 2, 2, 2, 2, 3, 1, 2] >>> list(accumulate(l)) [3, 6, 7, 10, 13, 15, 17, 19, 21, 24, 25, 27] >>>‍‍‍‍‍

DanPatterson_Retired · Answer

That was a demonstration of what to do

* import numpy as np  #  this is the python module that is needed
* variable 'a' ... I made an array of data to demonstrate the processes
* variable 'c'  .... I used one of the built-in function of numpy ... specifically 'cumsum' to get the result.  In python, when I imported numpy as np... np is now the numpy module with a 'nickname'.  I use 'module.function' to get a result.  In other words.... use the numpy cumulative sum function to get a cumulative sum  of variable 'a'.....therefore   c = np.cumsum(a)
* the second example... was just another example...
* the third example... is just an example of how to do cumulative sums the old-school way

That pretty well 'sums' it up from start to finish... cumulatively