import urllib.request
import os
import tarfile

#下载数据集
url="http://ai.stanford.edu/~amaas/data/sentiment/aclImdb_v1.tar.gz"
filepath="data/aclImdb_v1.tar.gz"
if not os.path.isfile(filepath):
    result=urllib.request.urlretrieve(url,filepath)
    print('downloaded:',result)
# 解压
if not os.path.exists("data/aclImdb"):
    tfile = tarfile.open("data/aclImdb_v1.tar.gz", 'r:gz')
    result=tfile.extractall('data/')