Python Basics
Python Basics

10X Genomics builds its own reference genome

... Rowan
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Python Basics

Use stringr to process strings

... Hudson
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Python Basics

The derivation and solution of PCA (3)-The role of PCA

... Sydney
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Python Basics

Polynomial regression

In linear regression, we are looking for a straight line to fit the data as best as possible. But we are not satisfied with simple linear regression in most cases. In the case of this special linear regression as shown in the figure below, this special regression method is called polynomial regression (Polynomial regression).The following data:import numpy as np import matplotlib.pyplot as plt plt.rcParams["figure.figsize"] = (8,6) x = np.random.uniform(-3, 3, size = 100) y = 2 * x ** 2 + 3 * x

... Eden
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Advanced Python
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Logistic regression of machine learning combat

... Justin
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trending_up Advanced Python

Naive Bayes of machine learning combat

... Summer
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trending_up Advanced Python

Decision tree for actual machine learning

... Eric
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KNN algorithm for machine learning

... Ella
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Advanced Python|Decorators (1)

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Python advanced | talk about several commonly used built-in functions

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Python Web Development
Python Web Development

Request for detailed explanation of web crawler framework Scrapy

Author: zarten, Internet front-line workers.Address: zhihu.com/people/zartenIntroductionThe Request class is an http request class, which is a very important class for crawlers. Usually such a request is created in Spider, and such a request is executed in Downloader. At the same time, there is also a subclass FormRequest inherited from it, used for post requests.Common usage in Spider:yield scrapy.Request(url ='zarten.com')The class attributes and methods are:url method headers body meta copy()

... Matthew
schedule 6 min read
Python Web Development

Summation problem in Python array

Author : dyq666, zhihu.com / people / dyq666This topic mainly introduces two methods of hash table and pointer to solve this kind of problem, from the sum of two numbers to the sum of three numbers, and then from the problem of the sum of four numbers, how to construct a universal Code (can solve the sum of N numbers). The main content of this article is to get a preliminary understanding of the two common methods of array summation through the 001 problem.001-Two SumGiven an integer array and a

... Max
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Python Web Development

Ultra-lightweight crawler framework: looter

♚Author : Half carriers War, Pythonistia && Otaku, an effort to change jobs in the surveying and mapping personnel desuHomepage: zhihu.com/people/ban-zai-liu-shangThe crawler has three steps in total: initiating a request-parsing the data-storing the data, which is enough to write the most basic crawler. Frameworks such as Scrapy can be said to integrate everything about crawlers, but newcomers may not use them very smoothly. Watching tutorials may also step on various pits, and Scrapy i

... Colton
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Machine Learning
Machine Learning

Python crawler crawling embarrassment encyclopedia paragraph example sharing

In this article, the editor compiled the content of examples about Python crawlers crawling embarrassment encyclopedia for everyone. Friends who need it can refer to it.This time, I will bring you an example of Python crawling the snippets of Embarrassing Encyclopedia.First of all, everyone has heard of Embarrassment Encyclopedia, right? A lot of funny jokes posted by embarrassing friends, this time we try to grab them with crawlers.The goal of this article1. Grab popular stories on the Encyclop

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Machine Learning

Teach you how to use Python to automatically send and receive emails

This article mainly introduces the method of automatically sending and receiving emails in Python. The sample code introduced in the article is very detailed. It has a certain reference value for everyone's study or work. Friends who need it, follow the teacher to learnAs a class representative, two things I often do are: helping to send homework and helping to receive homework, and most of the time it is done by mail. If you manually receive and send one by one, it will be a waste of time-life

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Machine Learning

Python爬虫获取豆瓣电影并写入excel

这篇文章主要介绍了Python爬虫获取豆瓣电影并写入excel ,文中通过示例代码介绍的非常详细，对大家的学习或者工作具有一定的参考学习价值,需要的朋友可以参考下豆瓣电影排行榜前250 分为10页，第一页的url为https://movie.douban.com/top250,但实际上应该是https://movie.douban.com/top250?start=0 后面的参数0表示从第几个开始，如0表示从第一（肖申克的救赎）到第二十五（触不可及），https://movie.douban.com/top250?start=25表示从第二十六（蝙蝠侠：黑暗骑士）到第五十名（死亡诗社）。等等，所以可以用一个步长为25的range的for循环参数复制代码 代码如下:for i in range(0, 250, 25): print(i)分析完页面组成后，开始获取页面，直接request.get()发现没有返回任何东西，输出一下响应码url = 'https://movie.douban.com/top250?start=0'res = request.get(url=url)print(

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Machine Learning

Python crawler realizes automatic login and sign-in functions with code

This article mainly introduces the code of Python crawler to realize automatic login and sign-in functions. This article introduces you in the form of pictures and texts in detail. It has a certain reference value for everyone's study or work. Friends who need it can refer to I downloaded something on a material website a few days ago. The points are always not enough. How did the points come? I log in to the website every day to sign in. Of course I can buy them. I don’t want to buy them becaus

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Machine Learning

The old Python driver will take you to write crawlers hand in hand, download the girl pictures from the whole site, and it’s cool enough!

Today, I will take everyone to write a simple and complete crawler. Let's grab the pictures of the entire site and save them on the computer! Ready to workTools: Python3.6, pycharmLibrary: requests, re, time, random, osTarget website: sister map (please go to the code to see the specific url...)Before writing codeBefore we start to write the code, we must first analyze the website, focusing on these points:1. First judge whether the webpage is a static webpage, this is related to the crawling me

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Machine Learning

Python game development and production AI greedy snake!

Prerequisite: This article implements the AI ​​Snake Battle by itself, plus the human-machine battle, and readers can add computers VS computers and players VS players on the basis again (in fact, after the human-computer battle is finished, these two are nothing, the idea is the same )Realize the effect:Specific functions:1. Smart mode: the computer plays by itself (eats food by yourself)2. Human-computer battle: computer and human operation (add a keyboard controlled snake on the basis of the

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Machine Learning

Want to switch to Python? What kind of technology should novices focus on learning?

What do people use Python for?Do website backend: There are a large number of mature frameworks, such as django, flask, bottle, tornadoWriting web crawlers: Python is very simple to write crawlers, and the library is very soundScientific Computing: Participate in the mathematical modeling contest, which can completely replace R language and MATLABData Mining: Machine Learning: There are many machine learning packages for PythonData Science: Recently Spark and Hadoop have opened Python interfaces

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