Many problems encountered in Python version management and python installation / uninstallation (MAC version)

Beginners in Python know that the Mac comes with Python 2 7, but we may use Python 3. *, Therefore, multi version management of Python is very important. This paper will use pyenv for multi version management of Python. 1. Install pyenv First, we need to install brew. If not, the installation method is as follows: /usr/bin/ruby -e "$(curl -fsS ...

Posted by argyrism on Sat, 07 May 2022 21:54:01 +0300

Python processes and threads

In order to run multiple tasks at the same time, python introduces the concept of multithreading. In Python, you can start multithreading mode in a convenient and quick way. Multithreading is often used in programs that conform to the concurrency mechanism, such as network programs. In order to further subdivide work ta ...

Posted by chrisprse on Sat, 07 May 2022 21:03:36 +0300

Python3: concurrent.futures achieves high concurrency.

  From: https://www.cnblogs.com/weihengblog/p/9812110.html concurrent. Official documents of Futures: https://docs.python.org/3/library/concurrent.futures.html concurrent. Future: thread pool enables you to handle tasks more efficiently and concurrently: https://www.h3399.cn/201906/703751.html     Because of its global interpreter lock GIL, py ...

Posted by show8bbs on Sat, 07 May 2022 10:33:26 +0300

[Backtracking interview questions] facebook interview questions - letter combinations of phone numbers (two solutions)

content Topic description Backtracking solution Solve using queues Topic description Title address: https://leetcode-cn.com/problems/letter-combinations-of-a-phone-number/ Given a string containing only the numbers 2-9, return all letter combinations it can represent. The mapping of numbers to letters is given as follows (same as phone k ...

Posted by johnpaine on Sat, 07 May 2022 10:12:49 +0300

Python learning notes 7: errors and exceptions

In the process of programming and running, we always encounter all kinds of errors. 1. Some errors are syntax errors when writing programs. For example, there are fewer colons, unreasonable indentation and so on. 2. Some errors are caused by problems in programming. For example, we should have output integer results and output string. This kind ...

Posted by PJNEW on Sat, 07 May 2022 08:27:02 +0300

Climb to station b video comment user information! These comments are the great God!

Recently, Mr. Ma Baoguo is very popular in station b. the video playback volume of him is very high. The video comment area of station b is full of talents who speak well. Write a crawler to crawl the user information and comment content in the comment area of station b. 1, Preparatory work 1. Tools (1) Chrome Google browser installation add ...

Posted by Hiro on Sat, 07 May 2022 07:36:40 +0300

Image recognition using ResNet18 residual network model of CIFAR10 data set - with an accuracy of 90%

Image recognition experiment using ResNet18 residual network model of CIFAR10 data set - accuracy of 90% (detailed notes attached) Auther:Yuandong Li Date: 2020/11/17 Welcome to my github: Li-Y-D The source code of this experiment and the code file in Jupyter Notebook format: Image-classification-CIFAR10-ResNet18 I Test requirements: Use Jup ...

Posted by cretam on Sat, 07 May 2022 04:50:48 +0300

Using Mask R-CNN in OpenCV

This article is translated from: https://www.pyimagesearch.com/2018/11/19/mask-r-cnn-with-opencv/ Transfer failed In this tutorial, you will learn how to use Mask R-CNN in OpenCV. Using Mask R-CNN, you can automatically segment and construct pixel level masks for each object in the image. We will apply Mask R-CNN to images and video stream ...

Posted by Frame on Sat, 07 May 2022 01:50:23 +0300

Scrapy watercress search page crawler

Scrapy watercress search page crawler Use the scratch crawler framework to crawl the search results of Douban books Scrapy Scrapy is an application framework written for crawling website data and extracting structural data It can be applied to a series of programs including data mining, information processing or storing historical data It provi ...

Posted by seavers on Sat, 07 May 2022 00:25:22 +0300

A bug triggered a contest between hair. I won an overwhelming victory. Can you keep your hair?

I met a very strange problem while debugging the company's project a few days ago. Today I'll study it here Follow official account: Java architects alliance, update technical articles every day scene As a PDA interface is newly added to the company to query the historical parking flow data, I first check the qualified data from the database ...

Posted by Sangre on Fri, 06 May 2022 20:42:28 +0300