【Python】使用 requests_toolbelt 发multipart/form-data 请求

1、multipart/form-data 请求

比较常见的 content-type 一般是以下2种：

application/json
application/x-www-form-urlencoded

使用requests发网络请求时，只要在data or json里带上对应的数据就能正常发请求了。

但是——
multipart/form-data 数据直接在放到data 里，一定报错。
这时，需要转码一下.

2、multipart/form-data 参数转码

比如请求参数是：

--e0ed233c-3202-47c6-9c96-f9181e308
Content-Disposition: form-data; name="id"
Content-Transfer-Encoding: binary
Content-Type: application/json; charset=UTF-8
Content-Length: 13

234545878
--e0ed233c-3202-47c6-9c96-f9181e308
Content-Disposition: form-data; name="type"
Content-Transfer-Encoding: binary
Content-Type: application/json; charset=UTF-8
Content-Length: 1

1
--e0ed233c-3202-47c6-9c96-f9181e308--

也就是说，有2个 key -> id 和 type

fields={
    
    
        "id": '234545878',
        "type": '1'
    }

直接这样发请求，会失败。⬆️

encode一下就能发请求了。⬇️

from requests_toolbelt.multipart.encoder import MultipartEncoder

multipart_data = MultipartEncoder(
    fields={
    
    
        "id": '1653302392217',
        "read_duration_list": read_duration_list,
        "now": now,
        "type": '1'
    }
)
header['Content-Type'] = multipart_data.content_type
header['accept'] = 'application/json'

3、一个实际案例

import requests
from requests_toolbelt.multipart.encoder import MultipartEncoder

upload_url = "https://api.code.com/upload"

now = str(get_msec())
read_duration_list= '[{"id":234545878,"type":2,"duration":11,"start_time":'+str(now)+',"trigger_page":"PersonalPage"}]'

multipart_data = MultipartEncoder(
    fields={
    
    
        "id": '1653302392217',
        "read_duration_list": read_duration_list,
        "now": now,
        "type": '1'
    }
)
header['Content-Type'] = multipart_data.content_type
header['accept'] = 'application/json'

upload = requests.post(upload_url, header=header, data=multipart_data)
print(f"upload:{
      
      upload}")