Tests to see if a PauliTerm or PauliSum is zero.

    :param pauli_object: Either a PauliTerm or PauliSum
    :returns: True if PauliTerm is zero, False otherwise
    :rtype: bool

def is_zero(pauli_object):
    """
    Tests to see if a PauliTerm or PauliSum is zero.

    :param pauli_object: Either a PauliTerm or PauliSum
    :returns: True if PauliTerm is zero, False otherwise
    :rtype: bool
    """
    if isinstance(pauli_object, PauliTerm):
        return np.isclose(pauli_object.coefficient, 0)
    elif isinstance(pauli_object, PauliSum):
        return len(pauli_object.terms) == 1 and np.isclose(pauli_object.terms[0].coefficient, 0)
    else:
        raise TypeError("is_zero only checks PauliTerms and PauliSum objects!")