How to send POST request?

This is a solution without any external pip dependencies, but works only in Python 3+ (Python 2 won't work):

from urllib.parse import urlencode
from urllib.request import Request, urlopen

url = 'https://httpbin.org/post' # Set destination URL here
post_fields = {'foo': 'bar'}     # Set POST fields here

request = Request(url, urlencode(post_fields).encode())
json = urlopen(request).read().decode()
print(json)

Sample output:

{
  "args": {}, 
  "data": "", 
  "files": {}, 
  "form": {
    "foo": "bar"
  }, 
  "headers": {
    "Accept-Encoding": "identity", 
    "Content-Length": "7", 
    "Content-Type": "application/x-www-form-urlencoded", 
    "Host": "httpbin.org", 
    "User-Agent": "Python-urllib/3.3"
  }, 
  "json": null, 
  "origin": "127.0.0.1", 
  "url": "https://httpbin.org/post"
}

You can't achieve POST requests using urllib (only for GET), instead try using requests module, e.g.:

Example 1.0:

import requests

base_url="www.server.com"
final_url="/{0}/friendly/{1}/url".format(base_url,any_value_here)

payload = {'number': 2, 'value': 1}
response = requests.post(final_url, data=payload)

print(response.text) #TEXT/HTML
print(response.status_code, response.reason) #HTTP

Example 1.2:

>>> import requests

>>> payload = {'key1': 'value1', 'key2': 'value2'}

>>> r = requests.post("http://httpbin.org/post", data=payload)
>>> print(r.text)
{
  ...
  "form": {
    "key2": "value2",
    "key1": "value1"
  },
  ...
}

Example 1.3:

>>> import json

>>> url = 'https://api.github.com/some/endpoint'
>>> payload = {'some': 'data'}

>>> r = requests.post(url, data=json.dumps(payload))

If you really want to handle with HTTP using Python, I highly recommend Requests: HTTP for Humans. The POST quickstart adapted to your question is:

>>> import requests
>>> r = requests.post("http://bugs.python.org", data={'number': '12524', 'type': 'issue', 'action': 'show'})
>>> print(r.status_code, r.reason)
200 OK
>>> print(r.text[:300] + '...')

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
<title>
Issue 12524: change httplib docs POST example - Python tracker

</title>
<link rel="shortcut i...
>>> 

Use requests library to GET, POST, PUT or DELETE by hitting a REST API endpoint. Pass the rest api endpoint url in url, payload(dict) in data and header/metadata in headers

import requests, json

url = "bugs.python.org"

payload = {"number": 12524, 
           "type": "issue", 
           "action": "show"}

header = {"Content-type": "application/x-www-form-urlencoded",
          "Accept": "text/plain"} 

response_decoded_json = requests.post(url, data=payload, headers=header)
response_json = response_decoded_json.json()
 
print(response_json)