python 如何读取目录下所有文件

# import os
# t = []
# for root, dirs, files in os.walk("./data/IMDBtest/pos", topdown=False):
#     for name in files:
#       with open(os.path.join(root, name),encoding='utf-8') as f:
#         a = f.read()
#         t.append(a)
#         print(a)