python runtime_error ai_generated true

RuntimeError: generator already executing

ID: python/runtimeerror-generator-already-executing

Also available as: JSON · Markdown
85%Fix Rate
88%Confidence
50Evidence
2023-01-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
311 active — — —

Root Cause

Generator's next() called while it's still running. Common in async code or recursive generators.

generic

Workarounds

  1. 92% success Don't call next() on a generator from within that generator's code path 
    Refactor to avoid calling next(gen) from within gen's own iteration

    Sources: https://docs.python.org/3/reference/expressions.html#generator-expressions

  2. 88% success Use separate generator instances for recursive patterns 
    Use separate generator instances for recursive patterns

    Sources: https://docs.python.org/3/reference/expressions.html#yield-expressions

Dead Ends

Common approaches that don't work:

  1. Use threading lock on the generator 75% fail

    Generators are not thread-safe by design — restructure instead

  2. Convert to list to avoid generator issues 55% fail

    Loses lazy evaluation and may cause memory issues

Error Chain

Preceded by: