Python

Recently in the study of Python, natural contact with the crawler, wrote a small crawler software, from the initial URL to parse the page, using the regular to get to crawl the link, using BeautifulSoup parsing to get the text, using their own

Title: "Python Algorithm for image histogram equalization"date:2018-06-12t17:10:48+08:00Tags: [""]Categories: ["Python"] Code#!/usr/bin/env Python3# Coding=utf-8ImportMatplotlib.image asMpimg fromMatplotlibImportPyplot

Grammar:try： try_suiteexcept Exception1: #只捕获特定的异常 suite1_exception1except Exception2，e： #捕获所列的异常和其额外的数据 suite2_exception2except (Exception3,Exception4): #捕获任何列出的异常

1 classPerson (object):2 def __init__(self,name,age):3Self.name =name4Self.age = Age5 defEat (self):6 Print('----%s is eating------'%self.name)7 8 defRun (self):9 Print('-----%s-----'%self.name)Ten One #How do I add a run to an

Errors and Exceptions: Error: Nameerror undeclared, initialized object Indexerror sequence does not have this index SYNTAXERROR syntax error keyboardinterrupt user-side Execution Eoferor no built-in input, reaching EOF tag Ioerro T input/Output

Yesterday reviewDict:dic = {'name':'Alex'} added: dic[' Age'] = 21presence on overwrite Dic.setdefault () does not increase Delete: Pop () is deleted by key, with return value cleardeldic['name'] Popitem () random delete returned is Ganso update Dic.

This brings us 4 mind map, combing the Python crawler Core Knowledge Points: Network basics, Requests,beautifulsoup,urllib and scrapy crawler framework.Crawler is a very interesting topic, this article is through the crawler completed the task of

Closure function:What is a closure function:Closed refers to the definition within a functionA package refers to a function that contains a reference to the name of an outer scope (not a global scope)Def counter (): N=0 def incr (): nonlocal n x=n n+

#!/usr/bin/python#_ *_ Coding:utf-8 _*_#Author: Moshell#datetime: 2018/6/11 9:28Import SysF1=open (R ' Account_password.txt ', ' R ')F2=open (R ' Lock_account.txt ', ' R ')info={}Lock=[]For line in F1:K,v=line.strip (). Split ()Info[k]=vFor line in

Operation PriorityStarting from elementary mathematics, we study the priority of operations, such as "first multiplication, then plus minus" in arithmetic, which indicates that multiplication and division have higher priority than addition and

The idea of binary tree realization1. Consider each node as an object that contains the following characteristics:The current value of the nodeThe left child of the node (a node object that stores a smaller value than the current node)Node right

PS: This parameter is really useless.When downloading large files, it is recommended to use Strea mode.By default, False, he will immediately begin to download files and put into memory, if the file is too large can lead to low memory situation.When

Class ==> instantiating ==> instance objects__init__ constructor functionSelf.name = Name # property, member variabledef sayhi () # method, dynamic propertydef get_heart (self):Return Self.__heart # provides an external access interface, but the

Python has an important concept, and everything is object.Everything can be assigned to variables:Built-in type assignment:1 >>> a=12 >>> b='abc'3 >>> Type (a)4 class'int'>5 >>> Type (b)6 class'str'>Assign a class type to a variable:1 >>> a=int2 >>

Big data analysis, how to make the data friendly display it? Of course, using charts, this article has Python's third-party library to complete the method of converting data to a chartNeed to use third-party libraries Pyecharts1. Pyecharts

Installation of 1.Requests modules1 PIP3 Install requests1 # Call: 2 Import Requests 3 4 response = Requests.get ('https://www.baidu.com')5 6 Print (Response.url) 7 Print (Response.text)View Code2.selenium + webdriver ModuleInstalling Selenium1 pip3

---restore content starts---Programming with languages such as JavaScript and Python that support the object-oriented paradigm involves the concept of closures and the use of closures . We'll discuss these two aspects today. Closures:The first is

Throw the question:Ask an array such as L = [0, 1, 2, 3,-4, 5,-6], and the number of the largest contiguous subarray of the array as the result of [0,1,2,3,-4,5] and 7Problem Analysis:The problem is simple, the direct violence Law, on the

Methods for time built-in modules1, Time () timestampTime (), floating point number floatReturn the current time in seconds since the Epoch.Fractions of a second may be present if the system clock provides them.Import Time Print (Time.time ())

1. Use while loop input 1 2 3 4 5 6 8 9 10i=1while(i2. For all numbers of 1-100i=1total=0while(i3. All odd numbers in output 1-100i=1total=0while(i4. All even numbers in output 1-100i=2total=0while(i5, Beg 1-2+3-4+5 ... 99 of all numbers of the andi=