python index_error ai_generated true

IndexError: list index out of range

ID: python/indexerror-list-out-of-range

Also available as: JSON · Markdown
90%Fix Rate
92%Confidence
50Evidence
2023-01-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
311 active — — —

Root Cause

Accessing a list index that doesn't exist. Common in loops, API responses, and off-by-one errors.

generic

Workarounds

  1. 92% success Check len() before access or use try/except with clear fallback logic 
    if idx < len(items): val = items[idx]

    Sources: https://docs.python.org/3/library/functions.html#len

  2. 88% success Use negative indexing or slice notation for safe tail access 
    last = items[-1] if items else default

    Sources: https://docs.python.org/3/library/stdtypes.html#sequence-types-list-tuple-range

Dead Ends

Common approaches that don't work:

  1. Wrap in try/except IndexError 70% fail

    Masks the real issue — the list is shorter than expected

  2. Pad list with None values 60% fail

    Introduces None downstream which causes TypeError later

Error Chain

Leads to:
Preceded by: