nan-comparison / W0177

Message emitted:

Comparison %s should be %s

Description:

Used when an expression is compared to NaN values like numpy.NaN and float('nan').

Problematic code:

import numpy as np


def both_nan(x, y) -> bool:
    return x == np.NaN and y == float("nan")  # [nan-comparison, nan-comparison]

Correct code:

import numpy as np


def both_nan(x, y) -> bool:
    return np.isnan(x) and np.isnan(y)

Created by the basic checker.