assert和raise

def func():
    try:
        x = 1
        y = 0
        assert x + y == 0, 'x +y != 0, x + y is {}'.format(x + y)
    except AssertionError as err:
        # raise AssertionError('abc ')
        # raise AssertionError
        # raise
        raise err


def func2(a, b):
    try:
        a + b
        func()
    except Exception as error:
        print('error {} has occured'.format(error))

func2(2, 3)
# 调用func2 之后输出的如下：
# raise err 对应输出是error x +y != 0, x + y is 1 has occured
# raise 对应输出是error x +y != 0, x + y is 1 has occured
# raise AssertionError('abc')输出是error abc  has occured
# raise AssertionError 输出是error  has occured

raise AssertionError会传递一个AssertionError的实例，而不是此时捕获的error

Python 中的assert

def func():
    try:
        x = 1
        y = 0
        assert x + y == 0, 'x +y != 0, x + y is {}'.format(x + y)
        # 输出的是AssertionError: x +y != 0, x + y is 1
        # assert x + y == 0
        # 没有输出
    except AssertionError as err:
        print(err)
func()
# 如果是 assert condiction, message 的形式，只会打印出错误信息，不会输出条件表达式
# 如果是 assert condiction的形式，Python不会输出条件表达式

Pytest 中的assert 会OverwritePython 中的assert

def test():
    try:
        x = 1
        y = 0
        assert x + y == 0, 'x +y != 0, x + y is {}'.format(x + y)
        # 输出的是x +y != 0, x + y is 1, assert 1 == 0
        # assert x + y == 0
        # 输出的是 assert 1 == 0
    except AssertionError as err:
        print(err)

# Pytest 不管是assert condiction, message 的形式还是assert condiction，都会输出条件表达式