我def了两个参数 但是给2个却报错

import os
def get_file_name(file_dir,file_type):
    L=[]
    for root, dirs, files in os.walk(file_dir):
        for file in files:
            if os.path.splitext(file)[1] == file_type:
                L.append(os.path.join(root, file))
    return L

调用 

L=user_func.get_file_name('c:\\mypython\\test','.xlsx')
==============
takes 1 positional argument but 2 were given