refactor(proxy-checker): tighten anonymity typing and remove unused imports

- remove unused imports (json, os, time, Any)
- add `Literal["Transparent","Anonymous","Elite",""]` return type to `parse_anonymity`
- change `ProxyChekerResult.anonymity` to `Literal["Transparent","Anonymous","Elite",""]`
- import `Literal` where required for stricter static typing

Author: dimaslanjaka

proxy_checker/ProxyChecker.py

@@ -1,10 +1,7 @@
-import json
-import os
 import random
 import re
-import time
 from io import BytesIO
-from typing import Any, Optional, Union
+from typing import Optional, Union, Literal
 
 import certifi
 import pycurl
@@ -157,7 +154,9 @@ def send_query(
 
         return {"timeout": timeout, "response": resp_text, "total_time": total_time}
 
-    def parse_anonymity(self, response: str) -> str:
+    def parse_anonymity(
+        self, response: str
+    ) -> Literal["Transparent", "Anonymous", "Elite", ""]:
         if not self.ip:
             return ""
 

proxy_checker/ProxyChekerResult.py

@@ -1,13 +1,13 @@
 from dataclasses import dataclass
-from typing import List, Optional
+from typing import List, Optional, Union, Literal
 from dataclasses import asdict
 import json
 
 
 @dataclass
 class ProxyChekerResult:
     protocols: List[str]
-    anonymity: str
+    anonymity: Literal["Transparent", "Anonymous", "Elite", ""]
     latency: int
     country: Optional[str] = None
     country_code: Optional[str] = None