feat: cached fetch

cnet.py

@@ -0,0 +1,45 @@
+import json as json_module
+import os
+from typing import cast
+import requests
+
+CACHE_DIR = ".cached"
+DEBUG = True
+
+
+def _escape_path(url: str) -> str:
+    if not os.path.exists(CACHE_DIR):
+        os.makedirs(CACHE_DIR)
+    path = url
+    for char in [":", "/", "?", "&", "=", "%", ".", " "]:
+        path = path.replace(char, "_")
+    return os.path.join(CACHE_DIR, path[:250])
+
+
+def text(url: str) -> str:
+    cache_path = _escape_path(url)
+
+    if os.path.exists(cache_path):
+        with open(cache_path, "r", encoding="utf-8") as f:
+            if DEBUG:
+                print(f"From cache: {url}")
+            return f.read()
+
+    response = requests.get(url)
+    response.raise_for_status()
+    content = response.text
+
+    with open(cache_path, "w", encoding="utf-8") as f:
+        _ = f.write(content)
+
+    if DEBUG:
+        print(f"Fetch: {url}")
+    return content
+
+
+type JVal = dict[str, "JVal"] | list["JVal"] | str | int | float | bool | None
+
+
+def json(url: str) -> JVal:
+    raw_text = text(url)
+    return cast(JVal, json_module.loads(raw_text))