pylint-errors
W0631 (undefined-loop-variable)
Problematic code:
data = {'x': 1, 'y': 2, 'z': 3} for k, v in data.items(): x = f'key: {k} => value: {v}' break print(x) 
Correct code:
data = {'x': 1, 'y': 2, 'z': 3} x = None for k, v in data.items(): x = f'key: {k} => value: {v}' break print(x) Rationale:
Used when a loop variable (i.e. defined by a for loop or a list comprehension or a generator expression) is used outside the loop.