如何正确断言pytest中引发了异常？

Question

码：# coding=utf-8import pytestdef whatever():    return 9/0def test_whatever():    try:        whatever()    except ZeroDivisionError as exc:        pytest.fail(exc, pytrace=True)输出：================================ test session starts =================================platform linux2 -- Python 2.7.3 -- py-1.4.20 -- pytest-2.5.2plugins: django, covcollected 1 items pytest_test.py F====================================== FAILURES ======================================___________________________________ test_whatever ____________________________________    def test_whatever():        try:            whatever()        except ZeroDivisionError as exc:>           pytest.fail(exc, pytrace=True)E           Failed: integer division or modulo by zeropytest_test.py:12: Failed============================== 1 failed in 1.16 seconds ==============================如何使pytest打印回溯，所以我会看到在whatever函数中引发异常的地方？

Answer 1

您的意思是这样的吗：

def test_raises():

    with pytest.raises(Exception) as excinfo:   

        raise Exception('some info')

    # these asserts are identical; you can use either one   

    assert execinfo.value.args[0] == 'some info'

    assert str(execinfo.value) == 'some info'