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51. Create a structured array (★★☆) representing position (x, y) and color (r, g, b, a)(prompt: dtype)Z = np.zeros(10, [('position', [('x', float, 1),                                  ('y', float, 1)]),                   ('color',    [('r', float, 1),                                  ('g', float, 1),                                  ('b', float ...

Serial communication of Python Serial communication is a necessary skill for embedded engineers. If you can write a simple host computer, you will get a lot of points. This series is a record of relevant work. After all, Python is not often used and always forgets a lot of things. It's too much trouble to learn it again when you use it. After ...

preface The book continues from the above: This paper builds the third wheel, which is also a very common function gather in the asyncio package 1, Knowledge preparation ● compared with the first two functions, gather is used more frequently because it supports the "simultaneous" execution of multiple collaborative tasks ● understa ...

First question   unexpected check-in questions, traversal. #FA Yi ans = 0 for i in range(1,2021): for j in str(i): if j == "2": ans += 1 print(ans) #Method II s=0 for i in range(1, 2021): s+=str(i).count('2') #The count function can only be used with strings, so you need to convert numbers to strings print ...

2.4 use optimistic lock to place orders concurrently Important: When multiple users initiate an order request for the same commodity at the same time, first query the commodity inventory and then modify the commodity inventory, there will be resource competition, resulting in abnormal final results of inventory. 2.4.1. Concurrent order probl ...

preface 🚀 Author: "programmer pear" 🚀 ** Article introduction * *: This article mainly explains how to use Python to find out those people who block me in QQ space, and put them in The whole process of pulling black. 🚀 ** Article source code acquisition * *: in order to thank everyone for paying attention to my little cu ...

Introduction: Hello, iron juice ~ I brushed such a short video on the subway today. I wonder if I can write a similar class roll call program. The idea can't stand waiting. Just write it~ 1, Preparatory work 1.Tkinter Tkinter is Python's built-in TK GUI tool set. TK is the native GUI Library of Tcl language. As a graphic design tool of ...

1, Understand what preprocessing is Data preprocessing is a data mining technology. Its essence is to convert the original data into an understandable format or in line with our mining format. 2, Why preprocessing In the real world, data is usually incomplete (lack of some interesting attribute values), inconsistent (including difference ...

  I summary In the last [crawler] article on deploying Scrapy to k8s, it was mentioned that errors were reported in the custom ， spiderkeeper ， image, so I submitted a ， python ， package called ， spiderkeeper new ， based on its source code to the ， pypi ， official website. This article will record the whole construction process and ...

05 application of branch and loop structure Classic case Example 1: Fibonacci sequence Note: the characteristic of Fibonacci sequence is that the first two numbers of the sequence are 1. Starting from the third number, each number is the sum of the first two numbers. Then the first ten numbers of Fibonacci sequence are: 1 1 2 3 5 8 13 21 ...