how to preserve values in a recorsive function in python

Question

the function must define the recursive function (or using your own recursive function) es68(dir, extensions), which must count how many files of certain types are in a directory or in one of its subdirectories, and which receives as arguments:

dir: the path to the directory to search extensions: extensions (the last letters of the name of the files we are looking for)

import os
import os.path
def es68(dir, estensioni): 

    c = 0
    for name in os.listdir(dir):
        if name.startswith('.'): continue
        if estensioni in name:
            c += 1            
        pathname = os.path.join(dir, name)
        if os.path.isdir(pathname): 
            es68(pathname, estensioni)
    return c

I expect the function to return me the number of times it encounters the extension. the problem is that every time the recursion is done the variable 'c' is reset to 0 and i don't know how to fix this. I would like the variable 'c' every time it increases by 1 to not reset

without changing the inputs of the function, it must be just dir and estensioni

Answer 1

You can accumulate the result of the recursive call back into c:

if os.path.isdir(pathname): 
    c += es68(pathname, estensioni)