Python请求库工作，urllib.request.urlopen POST不工作

import urllib.parse
import urllib.request

url = "http://example.com/post"
data = {"key1": "value1", "key2": "value2"}
data = urllib.parse.urlencode(data).encode("utf-8")

req = urllib.request.Request(url, data=data, method="POST")
response = urllib.request.urlopen(req)

import urllib.request

url = "http://example.com/post"
data = {"key1": "value1", "key2": "value2"}
data = urllib.parse.urlencode(data).encode("utf-8")

req = urllib.request.Request(url, data=data, method="POST")
req.add_header("Content-Type", "application/x-www-form-urlencoded")

response = urllib.request.urlopen(req)

import urllib.request
import ssl

url = "https://example.com/post"
data = {"key1": "value1", "key2": "value2"}
data = urllib.parse.urlencode(data).encode("utf-8")

context = ssl.create_default_context()
response = urllib.request.urlopen(url, data=data, context=context)