Articles/Python

KeyError in Python — What It Means and How to Fix It

What Python's KeyError exception means and how to resolve it.

Published October 27, 2026

KeyError is raised when a dictionary key that doesn't exist is accessed.

Key points

  • Catch it specifically with "except KeyError:" when you want to handle this exact case rather than a bare except

Example

d = {'a': 1}
d['b']  # KeyError: 'b'
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