EC
UnicodeWarning
PythonWARNINGCommonWarning

Unicode comparison or conversion issue

Quick Answer

Ensure both sides of a comparison are the same type — decode bytes to str or encode str to bytes before comparing.

Production Risk

Low.

What this means

Raised when a Unicode-related warning occurs — most commonly when comparing a Unicode string with a byte string in a way that cannot be resolved without a lossy conversion.

Why it happens
  1. 1Comparing str with bytes directly
  2. 2Legacy code mixing Python 2 unicode and str types under Python 3

Fix

Normalise types before comparison

Normalise types before comparison
# Decode bytes before comparing
raw = b'hello'
text = 'hello'
assert raw.decode('utf-8') == text  # safe

Why this works

Converting both operands to the same type (str) eliminates the ambiguity that triggers UnicodeWarning.

Same error in other languages
UnicodeDecodeErrorin Python→
Sources

Content generated with AI assistance and reviewed for accuracy. Found an error? hello@errcodes.dev

← All Python errors