examples/pytest/b3/banks.py
class NegativeDeposite(Exception):
    pass

class Bank(object):
    def __init__(self, start):
        self.balance = start

    def deposit(self, money):
        if money < 0:
            raise ValueError('Cannot deposit negative sum')
        self.balance += money
        return

examples/pytest/b3/error.txt
    def test_negative_deposit():
        b = Bank(10)
        with pytest.raises(Exception) as exinfo:
            b.deposit(-1)
>       assert exinfo.type == NegativeDeposite
E       AssertionError: assert <class 'ValueError'> == NegativeDeposite
E        +  where <class 'ValueError'> = <ExceptionInfo ValueError tblen=2>.type