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    There are three ways to apply self-defined or other library functions to Pandas objects: apply(): apply the function row by row or column by column agg() and transform(): aggregation and transformation applymap(): apply functions element by element 1, apply() Where: set the axis = 1 parameter, which can be operated line by line; The def ...

catalogue 1.1 review synchronized 1.2 Lock interface 1.3 Lock method 1.4 difference between the two 1.1 review synchronized It is a keyword of Java. It is a kind of synchronous lock, which can modify an object, variable and method, To control this modified, sequential access, Multithreaded programming steps: First: create a resource class, at ...

catalogue 1, Basic thread usage 1. Two ways to create threads 2. Thread application case 1 - inherit thread class 3. Thread application case - Implementation of Runnable interface 4. Thread application case - multithreaded execution 5. How do threads understand 2, The difference between inheriting thread and implementing Runnable 1. Cod ...

Record the problems encountered in recent work. The requirement is to customize the undo and restore functions in Vue quil editor rich text: undo and redo. install npm install vue-quill-editor -S Of course, you can also use CDN. Here we talk about NPM installation Mount in component import 'quill/dist/quill.core.css' import 'quill/dist/qui ...

1. Succinct JDBC (Java DataBase Connectivity) is a Java API for executing SQL statements. It can provide unified access to a variety of relational databases. It is composed of a group of classes and interfaces written in Java language. JDBC provides a benchmark by which more advanced tools and interfaces can be built to enable database develop ...

Design mode self study notes 003_Real (decorator design mode, adapter design mode) 1, Decorator design mode In the previous proxy design pattern, we expanded the methods in the class. Now, a class in Wu needs to add new functions, that is, it needs to add new methods to realize new functions. The first way is to create another class to inheri ...

Graphic verification code recognition technology: Hinder our reptiles. Sometimes it is the graphic verification code when logging in or requesting some data. So here we explain a technology that can translate pictures into words. Translating pictures into words is generally called Optical Character Recognition, abbreviated as OCR. There are not ...

Reproduced in this article: https://www.cnblogs.com/ricoo/p/10271919.html   This paper is undertaken by: https://www.cnblogs.com/seven1314pp/p/15958214.html After This section describes the link jump between different views in the same window. Premise: complete the previous step, and the MAIN view ALV is displayed. Back to the top 1. Effect dis ...

An example of Halcon two-dimensional affine transformation Handled at: https://www.cnblogs.com/xh6300/p/7442164.html Two dimensional affine transformation, as its name implies, is the behavior of translating, rotating, scaling and other transformations of objects in a two-dimensional plane (of course, there are other transformations, and onl ...

Install JDK Uninstall the JDK pre installed in the system. Linux comes with java, but it cannot be compiled without javac, so it needs to be uninstalled and reinstalled rpm -qa | grep openjdk Perform uninstall. Use -- nodeps to ignore dependencies during uninstall [root@localhost ~]# rpm -e --nodeps java-1.8.0-openjdk-headless-1.8.0.161-2. ...