https://www.cnblogs.com/xiehong/p/9050301.html
https://www.cnblogs.com/miniren/p/7268816.html
https://blog.youkuaiyun.com/qq_24373725/article/details/80692991
python3 post数据在json文件中:
1. for very large files.
files = {'file': open('import.json')}
re = requests.post(url,data=open('import.json','rb'),headers=headers)
print(re.json())
2.If you want to send a smaller file, send it as a string.
contents = open('example.json', 'rb').read()
r = requests.post(url, data=contents, headers=headers)