Средства и методы разработки

out = []
for dir in os.listdir("корень папок")
    with open("корень папок\\" + dir + "\\файл.c","r") as fi:
        for (match) in re.findall(r'([0-9a-fA-FxX]+)', fi.read()):
            out.append(match)
with open("out.c","w") as fo:
    fo.write( ','.join(out))