Programmer Think

Classes and object orientation (1) theory Relationship between class and object: 1. Object oriented is a programming idea 2. Class is a kind of grammar 3. Grammar is the basis of realizing programming ideas class Definition: a collection of objects with the same attributes (data members) and behaviors (functions), such as: Human beings are ...

String & Immutable 1. Concepts String classes are modified by final, and similar final-modified classes include wrapper classes such as Integer, Double, and so on. As we learned in our second grade, final-modified classes are inheritable. In Java, final-modified classes are called "immutable classes". Curious classmates may ask, ...

Double ended queue deque deque is a double ended queue, which can be inserted at the head and tail, or deleted at the head and tail. Its advantage is that it combines the advantages of vector and list, but realizes random access and header plug deletion. When the space is not enough and needs to be expanded, it does not need to be as compl ...

Add existing source code into repo management Applicable to the source code of non source code management (git/repo) in large projects preface ​ When the company is developing some projects, the code given from the supplier's original factory does not contain any source code management files. Many people need to cooperate in the developmen ...

Numerical descriptive statistics Arithmetic mean S = [s_1, s_2, ..., s_n] Each value in the sample is the sum of true value and error. mean = \frac{(s_1 + s_2 + ... + s_n) }{n} The arithmetic mean represents an unbiased estimate of the true value.m = np.mean(array) m = array.mean() m = df.mean(axis=0)Case: mean analysis of film scoring data:me ...

ping module ping is a common module to test whether the SSH connection of the remote node is ready. However, it is not as simple as the Linux command to ping the remote node. Instead, first check whether the remote node can log in through SSH, and then check whether its Python version meets the requirements. If it meets the requirements, it wil ...

Node. News crawler and network search (JS) Project requirements 1, Reptile part 1. Complete the web page analysis and crawler design of the target website. 2. Crawl no less than 100 pieces of data (each data includes 7 fields, news keywords, news titles, news dates, news authors, news sources, news abstracts and news contents), and store ...

   according to the business requirements that business developers usually face, we divide the log into operation (request) log and system operation log. The operation (request) log allows administrators or operators to easily query and track the specific operations of users in the system interface, so as to analyze and count user beh ...

problem To make an app for mui, you need to open a web page on one of the pages. And the web page can get the user information of the current application. solve 1. Create shell: It's easy to open a web page in the page: Create a shell with the following source code: Shell functions include: Get the required parameters of the current ...

Error content: 553 envelope sender mismatch with login user or Not connected It means that the sender does not match the login user, that is, the mailName and fromAddress do not match, but it is the same in the actual project. The following is the content collected online that can solve the problem. Recently, I found a special phenomenon in t ...