依赖第三方包

from requests_toolbelt import MultipartEncoder

import requests
from requests_toolbelt import MultipartEncoderm = MultipartEncoder(fields=quer_m,   # quer_m是post请求需要的参数boundary='------'+''.join(random.sample(string.ascii_letters + string.digits, 32))
)r = requests.post(search_url, data=m, content_type=m.content_type)
print r.status_code

requests直接构建

index_header = {"Accept": "*/*","Accept-Encoding": "gzip, deflate","Accept-Language": "zh-CN,zh;q=0.9","Connection": "keep-alive",# "Content-Length": "319",# "Content-Type": "multipart/form-data; boundary=----WebKitFormBoundaryZ5DTTaBI8Tbh6St8","Host": "<your host>","Origin": "<your origin>","Referer": "<your referer>","User-Agent": "<your ua>","X-Requested-With": "XMLHttpRequest",
}  # 注意不要传入Content-Typedata = {"method":(None,'queryWhjyxk'),"params":(None,json.dumps({"companyName":"","registrationNumber":""}))
}  #  post请求所有参数需要这样写入r = requests.post(search_url, files=data, headers=index_header)
print r.status_code