find-duplicate.py

#!/usr/bin/env python3
# find files with same extension inside sub-directories

import os

extensions = ['.c', '.cpp', '.cs', '.java', '.py', '.go', '.php']

for ext in extensions:

    dc = fc = 0
    for _, _, fs in os.walk('.'):
        c = sum(f.endswith(ext) for f in fs)
        if c > 1:
            for f in fs:
                if f.endswith(ext):
                    print(f)