我有一个场景,我在运行时动态运行函数,需要跟踪“本地化”范围.在下面的示例中,“startScope”和“endScope”实际上将创建“嵌套”级别(实际上,此本地化作用域中包含的内容不是打印语句…它是在其他地方发送数据的函数调用和嵌套跟踪那里.startScope / endScope只设置用于开始/结束当前嵌套深度的控制标志.

这一切都适用于跟踪嵌套数据,但是异常是另一回事.理想情况下,异常会导致当前本地化范围“掉出”并且不会结束整个函数(下面示例中的myFunction).

def startScope():
    #Increment our control object's (not included in this example) nesting depth
    control.incrementNestingDepth()

def endScope():
    #Decrement our control object's (not included in this example) nesting depth
    control.decrementNestingDepth()

def myFunction():
    print "A"
    print "B"

    startScope()
    print "C"
    raise Exception
    print "D"
    print "This print statement and the prevIoUs one won't get printed"
    endScope()

    print "E"

def main():
    try:
        myFunction()
    except:
        print "Error!"

运行它会(理论上)输出以下内容：

>>> main()
A
B
C
Error!
E

>>>

我很确定这是不可能的,因为我已经在上面写了 – 我只是想描绘一下我想要实现的那种最终结果.

Python中可能有这样的东西吗？

编辑：一个更相关(尽管很长)的实例如何使用它的例子：

class Log(object):
    """
    Log class
    """

    def __init__(self):
        #DataModel is defined elsewhere and contains a bunch of data structures / handles nested data / etc...
        self.model = DataModel()

    def Warning(self,text):
        self.model.put("warning",text)

    def ToDo(self,text):
        self.model.put("todo",text)

    def Info(self,text):
        self.model.put("info",text)

    def StartAdvanced(self):
        self.model.put("startadvanced")

    def EndAdvanced(self):
        self.model.put("endadvanced")

    def AddDataPoint(self,data):
        self.model.put("data",data)

    def StartTest(self):
        self.model.put("starttest")

    def EndTest(self):
        self.model.put("endtest")

    def Error(self,text):
        self.model.put("error",text)


#myScript.py

from Logger import Log

def test_alpha():
    """
    Crazy contrived example

    In this example,there are 2 levels of nesting...everything up to StartAdvanced(),and after EndAdvanced() is included in the top level...everything between the two is
    contained in a separate level.
    """

    Log.Warning("Better be careful here!")
    Log.AddDataPoint(fancyMath()[0])

    data = getSerialData()

    if data:
        Log.Info("Got data,let's continue with an advanced test...")

        Log.StartAdvanced()

        #NOTE: If something breaks in one of the following methods,then GOTO (***)
        operateOnData(data)
        doSomethingCrazy(data)
        Log.ToDo("Fill in some more stuff here later...")
        Log.AddDataPoint(data)

        Log.EndAdvanced()

    #(***) Ideally,we would resume here if an exception is raised in the above localized scope
    Log.Info("All done!  Log some data and wrap everything up!")
    Log.AddDataPoint({"data": "blah"})

    #Done


#framework.py

import inspect
from Logger import Log

class Framework(object):

    def __init__(self):
        print "Framework init!"
        self.tests = []

    def loadTests(self,file):
        """
        Simplifying this for the sake of clarity
        """

        for test in file:
            self.tests.append(test)

    def runTests(self):
        """
        Simplifying this for the sake of clarity
        """

        #test_alpha() as well as any other user tests will be run here
        for test in self.tests:
            Log.StartTest()

            try:
                test()
            except Exception,e :
                Log.Error(str(e))

            Log.EndTest()

#End