pytest之钩子函数中的参数call

1、参数call是类CallInfo类的对象，理解为测试用例的执行结果（result）或失败（exception）收集在call参数中

@attr.s(repr=False)
class CallInfo:
    """ Result/Exception info a function invocation. """

    _result = attr.ib()
    # Optional[ExceptionInfo]
    excinfo = attr.ib()
    start = attr.ib()
    stop = attr.ib()
    when = attr.ib()

    @property
    def result(self):
        if self.excinfo is not None:
            raise AttributeError("{!r} has no valid result".format(self))
        return self._result

    @classmethod
    def from_call(cls, func, when, reraise=None):
        #: context of invocation: one of "setup", "call",
        #: "teardown", "memocollect"
        start = time()
        excinfo = None
        try:
            result = func()
        except:  # noqa
            excinfo = ExceptionInfo.from_current()
            if reraise is not None and excinfo.errisinstance(reraise):
                raise
            result = None
        stop = time()
        return cls(start=start, stop=stop, when=when, result=result, excinfo=excinfo)

    def __repr__(self):
        if self.excinfo is not None:
            status = "exception"
            value = self.excinfo.value
        else:
            # TODO: investigate unification
            value = repr(self._result)
            status = "result"
        return "<CallInfo when={when!r} {status}: {value}>".format(
            when=self.when, value=value, status=status
        )

2、call有五个属性：call.result指测试用例的每个阶段的执行结果，一般为空列表，不知道原因

　　　　　　call.when指测试用例的执行阶段，setup、call、teardown

　　　　　　call.start指每个阶段的开始执行时间

　　　　　　call.stop指每个阶段的结束执行时间

　　　　　　call.excinfo指每个阶段如果执行失败，则显示这个阶段的异常信息，它是一个ExceptionInfo类的对象（_pytest._code.code.py.ExceptionInfo）

例子：在测试用例call阶段执行失败，可以看到call.excinfo的属性值为<ExceptionInfo NameError tblen=18>，指出了异常的测试用例的行数和异常类型

注意：如果测试用例失败了（任何阶段）， 调用call.result会报属性不存在的错误，详见请看源码_pytest.runner.py.CallIfo的result（）方法

testcase/test_getRegionCountry/test_GetRegionCountry.py::test_getRightrequest <CallInfo when='setup' result: []>
setup
[]
1585986048.5431032
1585986048.5431032
<CallInfo when='call' exception: call阶段>
call
<ExceptionInfo NameError tblen=18>
1585986048.5431032
1585986049.7831051
FAILED<CallInfo when='teardown' result: []>
teardown
[]
1585986050.2931058
1585986050.3031058