requests.exceptions.ProxyError: Proxy connection failed

ProxyError: Proxy connection failed

$ python -c "import requests; requests.get('https://example.com', proxies={'http': 'http://bad:9999'})"
Traceback (most recent call last):
  ...
requests.exceptions.ProxyError: Cannot connect to proxy.

Why this happens

Proxy URL is invalid, proxy unreachable, auth required, or protocol mismatch.

Fix

Use valid proxy URLs, include credentials if needed, or remove proxies.

Wrong code

import requests
proxies = {"http": "http://bad:9999"}
requests.get('https://example.com', proxies=proxies)

Fixed code

import requests
proxies = {
    "http": "http://user:[email protected]:3128",
    "https": "http://user:[email protected]:3128",
}
resp = requests.get('https://example.com', proxies=proxies, timeout=5)
print(resp.ok)