Send and receive simple JSON message over HTTP

Question

I want to send and receive some simple data over HTTP.

Here's the server side:

import time
import BaseHTTPServer
import json

HOST_NAME = 'localhost' 
PORT_NUMBER = 9000 

class MyHandler(BaseHTTPServer.BaseHTTPRequestHandler):
    def do_POST(self):
        print "You've got mail!"
        content_len = int(self.headers.getheader('content-length', 0))
        body = self.rfile.read(content_len)
        data = json.loads(body)
        print data

if __name__ == '__main__':
    server_class = BaseHTTPServer.HTTPServer
    httpd = server_class((HOST_NAME, PORT_NUMBER), MyHandler)
    print time.asctime(), "Server Starts - %s:%s" % (HOST_NAME, 
PORT_NUMBER)
    try:
        httpd.serve_forever()
    except KeyboardInterrupt:
        pass
    httpd.server_close()
    print time.asctime(), "Server Stops - %s:%s" % (HOST_NAME, PORT_NUMBER)

Here's the client side:

import requests
import json

url = 'http://localhost:9000'
data = {
    'date': 'the best day',
    'time': 'the best time',
    'name': 'Janet Smith'
}

r = requests.post(url, json=data)
print r.status_code
print r.json()

I'm getting this error:

Traceback (most recent call last): File "testSend.py", line 17, in

r = requests.post(url, json=data)

File "/Library/Python/2.7/site-packages/requests/api.py", line 116, in post return request('post', url, data=data, json=json, **kwargs)

File "/Library/Python/2.7/site-packages/requests/api.py", line 60, in request

return session.request(method=method, url=url, **kwargs)

File "/Library/Python/2.7/site-packages/requests/sessions.py", line 524, in request

resp = self.send(prep, **send_kwargs)

File "/Library/Python/2.7/site-packages/requests/sessions.py", line 637, in send

r = adapter.send(request, **kwargs)

File "/Library/Python/2.7/site-packages/requests/adapters.py", line 498, in send

raise ConnectionError(err, request=request)

requests.exceptions.ConnectionError: ('Connection aborted.',

BadStatusLine("''",))

EDIT: I was originally experiencing a server-side error as well, but looks like the issue might have been with a line of pasted code. I re-indented everything and now it works.

NameError: name 'self' is not defined That error shouldn't be possible with this code. Are you sure you've posted the code correctly? — John Gordon
The client error is obvious -- the server isn't running, so the client can't connect. — John Gordon
@JohnGordon positive that the code is as posted. Could you help me understand the client error? I get the same error when I am able to run the server (commented out the code that was causing server side error). — atjin

atjin atjin · Accepted Answer · 2019-05-11T16:12:45

Turns out there were several problems:

The server side error was due to copy pasting code. I needed to re-indent everything.
The client side error was fixed by adding self.send_response(200) to my DO_POST function on the server side
Doing #2 introduces a new "cannot decode json" error. This is because the response from the server does not contain a json message. So I just need to comment out the print r.json() line or send a json message on the server side.

Send and receive simple JSON message over HTTP

1 Answers