python runtime_error ai_generated true

werkzeug.routing.exceptions.BuildError: Could not build url for endpoint 'user_profile'. Did you forget to specify values for 'user_id'?

ID: python/flask-url-for-endpoint-not-found

Also available as: JSON · Markdown · 中文
80%Fix Rate
90%Confidence
0Evidence
2024-02-18First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.x active — — —

Root Cause

The url_for function is called for an endpoint that expects path parameters, but those parameters are not provided.

generic

中文

调用 url_for 函数时，端点需要路径参数，但未提供这些参数。

Workarounds

  1. 100% success 
    Provide required parameters: url_for('user_profile', user_id=123)
  2. 80% success 
    Make the parameter optional in the route definition: @app.route('/user/<int:user_id>', defaults={'user_id': 0})

Dead Ends

Common approaches that don't work:

  1. 100% fail

    The route requires user_id, so it cannot build the URL.

  2. 70% fail

    Inconsistent endpoint names cause confusion and may lead to other BuildErrors.