import os
rdirs = {"D:/disk/Users/Mike/Documents", "D:/disk/Documents"}

exts = {}

for rootdir in rdirs:
    for subdir, dirs, files in os.walk(rootdir):
        for file in files:
            ext = os.path.splitext(file)[1]
            if (ext in exts):
                exts[ext] += 1
            else:
                exts[ext] = 1

fn = {".cpp", ".py", ".java", ".c", ".pas"}
res = 0

for ext in fn:
    if (ext in exts):
        res += exts[ext]
        print(ext + ":", exts[ext])

print("---------")
print(res)