human
Here's a good function header given the following:
I wrote the below code

    def check_file(f, path):
        if (not (ignore_substring and (ignore_substring in f))):
            if (substring in f):
                compl_path = os.path.join(path, f)
                if os.path.isfile(compl_path):
                    return compl_path
        return False
    results = []
    if recursive:
        for (par, nxt, fnames) in os.walk(path):
            for f in fnames:
                fn = check_file(f, par)
                if fn:
                    results.append(fn)
    else:
        for f in os.listdir(path):
            if (ignore_invisible and f.startswith('.')):
                continue
            fn = check_file(f, path)
            if fn:
                results.append(fn)
    if check_ext:
        results = [r for r in results if (os.path.splitext(r)[(-1)] == check_ext)]
    return results

What's a good function header?
assistant
#Here's a good function header.

def find_files(substring, path, recursive=False, check_ext=None, ignore_invisible=True, ignore_substring=None):