Programmer Think

catalogue Draw a line chart 1 import pyplot 2 set the size of the drawing 3 drawing 3.1 setting the style of graphics 4 adjust the scale of the coordinate axis 5. Display and save graphics 6 Display Chinese in graphics 6.1 method 1: global setting (valid under Windows and Linux) 6.2 method 2: set Chinese font 7. Setting description i ...

Hello, everyone. I'm a meow in the IT industry. Python is one of the most popular languages at present. It is widely used by many people in data science, machine learning, web development, scripting and automation. Its simplicity and ease of use make it so popular. In this article, we will introduce 30 short code fragments that you can unders ...

Example analysis of simple crawler With the exchange rate crawler demonstration written before The website has been revised and this crawler code is invalid But let's put it out and give you an introduction to reptiles I am a novice, do not spray import requests from bs4 import BeautifulSoup link = "https://www.msn. Cn / zh CN / money / curr ...

Previous remarks In the introduction of the last article, we introduced the basic use of pytest. This article specifically explains the pre-processing and post-processing of use case execution in pytest. The pre-processing and post-processing of use case execution in pytest can be realized either by test fixture or by xunit style pre-proces ...

Lists are equivalent to arrays in other languages Multiple different data types can be stored in the list How to create a list: ① Use brackets [] ② Call the built-in function list() lst = ['hello', 'world', 98] lst2 = list(['hello', 'world', 98]) print(lst) print(lst2) print(lst[1]) # world print(lst[-2]) # world Features of the list: ① Th ...

catalogue 1, Manual derivation of logistic regression gradient descent implementation 2, Classification of iris by logistic regression Introduction to iris dataset Introduction to linear classifier Main steps of designing linear classifier 1. Collect a group of samples with category marks X={x1,x2,..., xN} 2. Determine a criterion functi ...

preface The difference of data types between python and c + + is a common problem in conversion. Some simple data types can be used in general, but many middle types cannot be used directly. When encountering such problems, boost The extract class provided by python is a convenient solution. This article is used to record my understanding of e ...

It is well known that crawler collection websites must use dynamic agents to avoid frequent restrictions on website access. However, in the process of collecting websites, even if dynamic agents are used, anti crawling errors of 403, 503 or 429 will still occur. Why? According to past experience, it is generally caused by the following reasons: ...

1, Basic framework Project tasks: Each person's physical fitness test includes four items: horizontal bar, sit ups, 30m x2 snake run and 3000m run, plus whether the body shape is qualified (BMI body mass index or PBF body fat percentage). Each original test data is converted into a score of 100 points through the standards specified by differ ...

Content summary Zombie process and orphan process Daemon Mutex (key) Message queue Implement inter process data interaction (IPC mechanism) Producer consumer model Thread theory Detailed content 1, Process supplement Zombie process and orphan process Zombie process After the main process code runs, it will not end directly, but wait for all ...