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0 Preface When it comes to processing loops, we are used to using for, while, etc., for example, printing the characters in each list in turn:   lis = ['I', 'love', 'python'] for i in lis:     print(i) I love python When the number of bytes of the printed content is small, it can be printed after all the bytes are loaded into memory. There ...

Bowen structureCustom functionVariable scopePython built-in functions I. function Functions in Python are collections of statements and expressions. There is no limit to the use of functions, just like other values in Python. For reusable code, you need to write a custom function for reuse. Functions can be divided into nonparametric functio ...

Several common classification algorithms are used to train iris data, and K-fold cross validation method is used for evaluation K-fold cross validation: sklearn.model_selection.KFold(n_splits=k, shuffle=False, random_state=None) Idea: the training / test data set is divided into n ﹣ splits mutually exclusive subsets, one of whi ...

1. Create an Auto class, including the number of tires, car color, body weight, speed and other attributes, and create instances through different construction methods. At least the car should be able to accelerate and slow down Another car class, CarAuto, inherits Auto, adds air conditioning and CD attributes, and re implements methods to cove ...

There are four common ways to create threads in Java. 1. Override the run() method of the Thread class. There are two forms of expression: 1) the new Thread object anonymously overrides the run() method package constxiong.concurrency.a006; /** * new Thread Object anonymous override run() method, start thread * @author ConstXiong ...

Kotlin is a static language that runs on Java virtual machines, Android s, and browsers. It is 100% compatible with JAVA. If you are familiar with Java, you will find that Kotlin still uses the classic JAVA collection framework, in addition to its own standard libraries. Introduction to kotlin First try the Kotlin code.The Book class contains t ...

1. isinstance and issubclass 1.1 isinstance isinstance(obj,cls) checks whether obj is a cls like object class Foo(object): 　　pass obj = Foo() isinstance(obj, Foo) Example: class Base(object): 　　pass class Foo(Base): 　　pass obj1 = Foo() print(isinstance(obj1,Foo)) # Check that the first parameter (object) is an instance of the ...

1. Script example of recursively listing files in directoryTo list the files in the directory, you can do the following: os.listdir() In [1]: import os In [4]: os.listdir('/root') Out[4]: ['.tcshrc', '.bash_history', '.bashrc', 'ENV', '.cache', '.config', '.cshrc', '.bash_logout', 'python', '.ssh', 'shell', '.bash_profile', '.ip ...

Making wheels by hand: realizing a simple dependency injection (1) Intro In the previous article, I mainly introduced the overall design and general programming experience of dependency injection. This article will start to write code and start to implement its own dependency injection framework. Class diagram Let's review the class diagram men ...

Class File The File class is in the java.io package. IO stands for input and output, input and output. Represents files and directories that are not platform related. You can create, delete, rename, but you cannot access the file content. Constants in the File class: import java.io.File; public class TestFileConst { public static void mai ...