[lang-ref] ( nan ) ( python )

def test_nan():
    import math
    from decimal import Decimal

    nan1 = float('nan')
    assert math.isnan(nan1)

    nan2 = math.nan
    assert math.isnan(nan2)

    nan3 = Decimal('NaN')
    assert math.isnan(nan3)

    assert nan1 != nan2
    assert nan1 != nan3