Python: How can I find all files with a particular extension?

Question

I am trying to find all the .c files in a directory using Python.

I wrote this, but it is just returning me all files - not just .c files.

Answer 1

for _,_,filenames in os.walk(folder):
    for file in filenames:
        fileExt=os.path.splitext(file)[-1]
        if fileExt == '.c':
            results.append(file)