python network_error ai_generated true

werkzeug.exceptions.NotFound: 404 Not Found: The requested URL was not found on the server. If you entered the URL manually please check your spelling and try again.

ID: python/flask-404-not-found-route

Also available as: JSON · Markdown · 中文
80%Fix Rate
85%Confidence
0Evidence
2024-05-16First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.x active — — —

Root Cause

The request URL does not match any registered route, often due to a missing url_prefix or trailing slash mismatch.

generic

中文

请求 URL 与任何已注册路由不匹配，通常由于缺少 url_prefix 或尾部斜杠不匹配。

Workarounds

  1. 90% success 
    for rule in app.url_map.iter_rules():
    print(rule, rule.methods)
  2. 92% success 
    app.register_blueprint(api_bp, url_prefix='/api/v1')

Dead Ends

Common approaches that don't work:

  1. 80% fail

    Masks real routing bugs and breaks API semantics.

  2. 75% fail

    Only fixes trailing-slash cases, not missing prefixes.