Python3: JSON POST Request WITHOUT requests library

Question

I want to send JSON encoded data to a server using only native Python libraries. I love requests but I simply can't use it because I can't use it on the machine which runs the script. I need to do it without.

newConditions = {"con1":40, "con2":20, "con3":99, "con4":40, "password":"1234"}  params = urllib.parse.urlencode(newConditions) params = params.encode('utf-8')  req = urllib.request.Request(conditionsSetURL, data=params) urllib.request.urlopen(req)         

My server is a local WAMP server. I always get an

urllib.error.HTTPError: HTTP Error 500: Internal Server Error

I am 100% sure that this is NOT a server issue, because the same data, with the same url, on the same machine, with the same server works with the requests library and Postman.

Answer 1

You are not posting JSON, you are posting a application/x-www-form-urlencoded request.

Encode to JSON and set the right headers:

import json  newConditions = {"con1":40, "con2":20, "con3":99, "con4":40, "password":"1234"}  params = json.dumps(newConditions).encode('utf8') req = urllib.request.Request(conditionsSetURL, data=params,                              headers={'content-type': 'application/json'}) response = urllib.request.urlopen(req) 

Demo:

>>> import json >>> import urllib.request >>> conditionsSetURL = 'http://httpbin.org/post' >>> newConditions = {"con1":40, "con2":20, "con3":99, "con4":40, "password":"1234"}  >>> params = json.dumps(newConditions).encode('utf8') >>> req = urllib.request.Request(conditionsSetURL, data=params, ...                              headers={'content-type': 'application/json'}) >>> response = urllib.request.urlopen(req) >>> print(response.read().decode('utf8')) {   "args": {},    "data": "{\"con4\": 40, \"con2\": 20, \"con1\": 40, \"password\": \"1234\", \"con3\": 99}",    "files": {},    "form": {},    "headers": {     "Accept-Encoding": "identity",      "Connection": "close",      "Content-Length": "68",      "Content-Type": "application/json",      "Host": "httpbin.org",      "User-Agent": "Python-urllib/3.4",      "X-Request-Id": "411fbb7c-1aa0-457e-95f9-1af15b77c2d8"   },    "json": {     "con1": 40,      "con2": 20,      "con3": 99,      "con4": 40,      "password": "1234"   },    "origin": "84.92.98.170",    "url": "http://httpbin.org/post" }