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This article introduces you how to analyze the Python development process, the content is very detailed, interested friends can refer to, hope to be helpful to you.

Python is a powerful advanced scripting language, which is powerful not only in its own functions, but also in its good expansibility. Because of this, Python development has begun to be favored by more and more people, and has been successfully applied in the development process of all kinds of large-scale software systems.

Different from other ordinary scripting languages, Python programmers can make functional extensions to Python using C or C++ with the help of API provided by Python language. Thus, we can not only make use of the convenient and flexible syntax and functions of Python, but also obtain almost the same execution performance as C or C++.

Slow execution is a common feature of almost all scripting languages. It is also an important factor that has been criticized by people. Python cleverly solves this problem through the organic combination with C language, so that the scope of application of script language has been greatly expanded.

When developing an actual software system with Python, it is often necessary to use C _ Python + to extend it. The most common situation is that a library written in C already exists. You need to use some of the library's features in the Python language, and you can do so with the extension provided by Python. In addition, because Python is essentially a scripting language.

Some functions implemented with Python may be difficult to meet the execution efficiency requirements of the actual software system. At this time, with the help of the extended functions provided by Python, these key code segments can be implemented in C or C++, so as to provide the execution performance of the program. This paper mainly introduces the C language extension interface provided by Python, and how to use these interfaces and Cmax Candle + language to extend the function of Python, and gives a concrete example to explain how to realize the function extension of Python.

Python is a scripting language implemented in C language, which has excellent openness and expansibility, and provides a convenient and flexible application program interface (API). This enables the programmer to extend the functions of the Python interpreter at all levels. Before we can extend the function of Python with C + +, we must first master the C language interface provided by Python interpretation.

Python development is an object-oriented scripting language, and all objects are represented in the Python interpreter as PyObject,PyObject structures that contain all member pointers of Python objects. And the type information and reference count of Python objects are maintained. When programming Python extensions, once the Python object is processed in C or C++, it means maintaining a PyObject structure.

In the C language extension interface of Python, most functions have one or more parameters of PyObject pointer type, and most of the return values are PyObject pointers. To simplify memory management, Python implements automatic garbage collection through the reference counting mechanism. Each object in Python has a reference count, which is used to count how many times the object has been referenced in different places.

Every time a Python object is referenced, the corresponding reference count increases by 1, and each time a Python object is destroyed, the corresponding reference is subtracted by 1. It is only when the reference count is 00:00 that the Python object is actually deleted from memory. The following example shows how the Python interpreter uses reference counting to manage Pyhon objects:

Example 1:refcount.py class refcount: # etc. R1 = refcount () # reference count is 1 R2 = R1 # reference count is 2 del (R1) # reference count is 1 del (R2) # reference count is 0, delete object

Correct maintenance of reference count is a key issue when dealing with Python objects in Cpicabet +, and memory leaks can easily occur if it is not handled properly. Python's C language interface provides macros to maintain reference counting, the most common of which is to use Py_INCREF () to increase the reference count of Python objects by 1, and Py_DECREF () to subtract the reference count of Python objects by 1.

This function is the interface between Python development and C function, with two parameters: self and args. The parameter self is used only when the C function is implemented as an inline method (built-in method), usually with a value of NULL. The parameter args contains all the parameters that the Python interpreter passes to the C function, which is usually obtained by using the function PyArg_ParseTuple () provided by the C language extension interface of Python.

Each item in the method list consists of four parts: the method name, the derived function, the way parameters are passed, and the method description. The method name is the name under which the method is called from the Python interpreter. The mode of parameter transfer specifies the specific form of parameter transfer from Python to C function.

The two optional methods are METH_VARARGS and METH_KEYWORDS, where METH_VARARGS is the standard form of parameter passing, which passes parameters between the Python interpreter and the C function through the tuple of Python. If the METH_KEYWORD method is adopted, the parameters between the Python interpreter and the C function will be passed between them through the dictionary type of Python.

As a powerful scripting language, Python will be more widely used in various fields. In order to overcome the problem of slow execution speed of script language, Python provides the corresponding C language extension interface. By implementing the key code that affects the execution performance in C language, it can greatly improve the running speed of scripts written in Python, so as to meet the actual needs.

On how to analyze the Python development process to share here, I hope that the above content can be of some help to you, can learn more knowledge. If you think the article is good, you can share it for more people to see.

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