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))