rules:
- id: cannot-cache-generators
  patterns:
  - pattern-inside: |
      @functools.lru_cache(...)
      def $FUNC(...):
          ...
          yield ...
  - pattern: functools.lru_cache(...)
  message: Generators can only be consumed once, so in most cases, caching them will
    cause an error when the already-consumed generator is retrieved from cache.
  languages:
  - python
  severity: WARNING
  metadata:
    category: correctness
    technology: [python]