Python callback function Usage Example analysis

This example describes the Python callback function usage. Share to everyone for your reference. The specific analysis is as follows:

There is always a certain interface between software modules, which can be divided into three categories: synchronous invocation, callback and asynchronous invocation. A synchronous call is a blocking call that is returned when the caller waits for the execution to complete, a one-way invocation, or a two-way invocation pattern, that is, the callee invokes the interface when the interface is called, and the asynchronous invocation is a mechanism similar to a message or event, but it is called in the opposite direction. The service of an interface notifies the client (that is, the interface that invokes the client) when it receives a message or an event occurs. Callbacks are very closely related to asynchronous calls, and we typically use callbacks to register asynchronous messages and to implement notification of messages through asynchronous calls. Synchronous calls are the simplest of the three, and callbacks are often the basis of asynchronous invocations, so here we focus on the implementation of callback mechanisms in different software architectures.

#call. Pyimport Calleddef Callback ():  print "in Callback" Def Main ():  #called. Test ()  Called.test_call ( Callback)  print "in call.py" main () #called. Py "" Def Test ():  print "in called.py Test ()" "" Def Test_call (p_ Call):  print "in called.py Test_call ()"  p_call () joe@joe:~/test/python$ python call.pyin called.py test_call () In Callbackin call.pyjoe@joe:~/test/python$

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