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After learning the python class mechanism, many people will encounter a production problem, which is actually too normal, because the development of any program is first designed and then programmed. The python class mechanism is just a kind of Programming method, if you insist on using the class to smash your problem, it will become even more awkward. It is a matter of minutes. In the past, software development was relatively simple, from task analysis to programming, and then to the program. The debugging can be done by one person or a group. However, with the rapid increase in the scale of software, the problems faced by the software are very complicated, and there are too many factors to be considered. The errors, hidden errors, and unknown errors generated in a software may reach an alarming degree, which is not It is completely resolved at the design stage.
Therefore, software development is actually a complete set of specifications, and what we have learned is only a small part of it. A complete development process needs to clarify the tasks of each stage, and proceed to the next stage under the premise of ensuring that one stage is correct. Software engineering
Object-oriented software engineering includes the following parts:
1. Object oriented analysis (OOA)
The system analysis stage in software engineering requires analysts and users to work together to make accurate analysis and clear expressions of user needs, and analyze what the software system should do from a broad perspective, rather than how to do it. Object-oriented analysis should be based on object-oriented concepts and methods. In the analysis of the task, from the objective existence of things and the relationship between things, Guinan finds related objects (the object’s “features” and “skills”) and The connection between objects, and the objects with the same attributes and behaviors are identified by a class.
Establish a demand model that can reflect this is the work situation. The model at this time is rough.
2. Object oriented design (OOD)
According to the demand model formed in the object-oriented analysis stage, each part is specifically designed.
The first is the design of the class, the design of the class may contain multiple levels (using inheritance and derivation mechanisms). Then put forward the ideas and methods of program design based on these classes, including the design of algorithms.
In the design phase, no specific computer language is involved, but a more general description tool (such as pseudo code or flowchart) is used to describe
3. Object oriented programming (OOP)
According to the result of object-oriented design, choose a computer language to write it as a program, it can be python
4. Object oriented test (OOT)
After the program is written, it must be strictly tested before it is used by the user. The purpose of the test is to find errors in the program and correct it.
The right-oriented test is to use the object-oriented method to test, with the class as the basic unit of the test.
5. Object-oriented maintenance (object oriendted soft maintenance, OOSM)
Just as any product requires after-sales service and maintenance, there will be some problems when the software is in use, or the software vendor wants to improve the performance of the software, which needs to modify the program.
Because the object-oriented method is used to develop the program, the maintenance of the application is easier.
Because of the encapsulation of objects, modifying one object has little effect on other objects. The use of object-oriented method to maintain the program greatly improves the efficiency of software maintenance and has high scalability.
Among the object-oriented methods, the earliest development must be object-oriented programming (OOP). At that time, both OOA and OOD had not yet been developed. Therefore, in order to write object-oriented programs, programmers must go deep into the field of analysis and design. Especially in the field of design, OOP at that time actually included the current OOD and OOP phases, which required relatively high requirements for programmers, and many people found it difficult to master.
Now designing a large software is carried out in strict accordance with the five stages of object-oriented software engineering. The work of these five stages is not completed by one person from beginning to end, but by different people. In this way, the OOP stage The task is relatively simple. Program writers only need to write programs in object-oriented language according to the ideas proposed by OOd.