Function _nan_equal

Lib/test/test_statistics.py:41–69

Return True if a and b are both the same kind of NAN. >>> _nan_equal(Decimal('NAN'), Decimal('NAN')) True >>> _nan_equal(Decimal('sNAN'), Decimal('sNAN')) True >>> _nan_equal(Decimal('NAN'), Decimal('sNAN')) False >>> _nan_equal(Decimal(42), Decimal('NAN')) False

(a, b)

    return math.copysign(1, x)

def _nan_equal(a, b):
    """Return True if a and b are both the same kind of NAN.

    >>> _nan_equal(Decimal('NAN'), Decimal('NAN'))
    True
    >>> _nan_equal(Decimal('sNAN'), Decimal('sNAN'))
    True
    >>> _nan_equal(Decimal('NAN'), Decimal('sNAN'))
    False
    >>> _nan_equal(Decimal(42), Decimal('NAN'))
    False

    >>> _nan_equal(float('NAN'), float('NAN'))
    True
    >>> _nan_equal(float('NAN'), 0.5)
    False

    >>> _nan_equal(float('NAN'), Decimal('NAN'))
    False

    NAN payloads are not compared.
    """
    if type(a) is not type(b):
        return False
    if isinstance(a, float):
        return math.isnan(a) and math.isnan(b)
    aexp = a.as_tuple()[2]
    bexp = b.as_tuple()[2]
    return (aexp == bexp) and (aexp in ('n', 'N'))  # Both NAN or both sNAN.


def _calc_errors(actual, expected):