python name_error ai_generated true

NameError: name 'variable' is not defined

ID: python/nameerror-not-defined

Also available as: JSON · Markdown
95%Fix Rate
95%Confidence
50Evidence
2023-01-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
311 active — — —

Root Cause

Variable or function referenced before assignment. Common after refactoring, conditional assignments, or typos.

generic

Workarounds

  1. 95% success Check for typos and ensure variable is assigned in all code paths 
    Check for typos and ensure variable is assigned in all code paths

    Sources: https://docs.python.org/3/reference/executionmodel.html#naming-and-binding

  2. 90% success Move import or assignment before first use; check conditional branches all assign 
    # Ensure all branches assign the variable:
if condition:
    result = compute()
else:
    result = default_value  # Don't leave this branch without assignment
# Also check: is the import above this line?

    Sources: https://docs.python.org/3/tutorial/controlflow.html

Dead Ends

Common approaches that don't work:

  1. Add global declaration 65% fail

    Usually masks a scoping issue rather than fixing it

  2. Initialize variable to None at module level 60% fail

    Hides the real bug — the variable should come from specific logic

Error Chain

Frequently confused with: