Python

Topic from Project Euler 14th: https://projecteuler.net/problem=14"Project Euler:problem 14:longest Collatz sequencethe following iterative sequence are defined for the set of positive INTEGERS:N→N/2 (n is even) n→3n + 1 (n was odd) Using the rule

One, for loopThe For loop is a very common loop in our programming, and here are some examples of applications for loops in Python:1. Single-layer for loop#!/usr/bin/env Python3#-*-Coding:utf-8-*-#user: Slim_liuFor I in range: #循环10次Print (i)

Why dictionary queries are fastCharacter encodingfunction definitionLocal variables, global variablesreturn valueNested functionsRecursive (two-point lookup)Ternary operationsMapLambaFunction-Type programmingHigher order functionsBuilt-in functionsA

Integer and Boolean type Gets the data type of the object 1. Type () 2. Dir () 3. Help () 4, in the pycharm inside the operation numeric type int Create: Int ()

Use Python to test the availability of a set of URLs in bulk (which can include HTTP status, response time, and so on) and count the number and frequency of unavailable situations.Similarly, such a script can determine the availability of a service

This script can be used to count the number of connected IPs on a port, and to count all IPs connected to that end, the maximum number of IPs and times, and the status of the TCP connection.Involves Python reading network connection statistics and

In object-oriented programming, exposed data members can be freely accessed and modified externally, which makes it difficult to control the legality of user's modification of the newly-updated data. A common way to solve this problem is to define

@property can access a Python-defined function as a property, providing a more friendly way to access it, but sometimes setter/getter is needed, why is it necessary to use functions as attributes?First, in order to provide friendly access, the

Python's Calling functionPython has built in a lot of useful functions that we can call directly.To invoke a function, you need to know the name and parameters of the function , such as an absolute function abs, which receives a parameter.

#!/bin/python#-*- coding=utf-8 -*-import stringprint ("Hello,world") str1 =  "        python is dynamic language         "#打印str1原型print (STR1) #打印去掉两边空格print (Str1.strip ()) #字符串大小写转换str2 = "Abcd efg,this is a test" Print (Str2.lower ())   #小写print

First, this is Python.For I in range (1): print ("". Join (["%d*%d=%d"% (j, I, I*j) for J in range (1, i+1)]))DetailedFor I in range (1): #当i = = 1 O'Clock: print ("". Join (["%d*%d=%d"% (j, I, I*j) for J in range (1, i+1)])) a ["%d*%d=%d"

English documents: delattr ( object , name ) This is a relative of setattr () . The arguments is an object and a string. The string must be the name of the one of the object ' s attributes.

The OS module provides new/delete/view file properties for directories or files, as well as path operations for files and directories. For example: absolute path, parent directory ...OS.SEP can replace the operating system-specific path delimiter. "\

filter, map, and reduce are all processed on a set, filter is easy to understand for filtering, map is used for mapping, and reduce is used for merging. Is the Python list method of three carriages.1. The function of the filter function corresponds

This plugin makes it easy to see many things, including HTML. Open the Watercress Movie Leaderboard top250 page, found that each page has 25 movies, altogether 10 pages, each page URL has the following characteristics: Http://movie.douban.com/top250

English documents: Help ([Object]) Invoke the built-in Help system. (This function is intended-interactive use.) If no argument is given, the interactive Help system starts on the interpreter console. If The argument is a string and then the string

1. Functional Programming1) conceptFunctional programming is a programming model that considers computer operations to be calculations of functions in mathematics and avoids the concept of state and Variable. WikiWe know that object is the first

The dictionary is the only type of mapping in python, its hash value (key Key) and the point to object (value) is a one-to-many relationship;A dictionary is a mutable object, is a container type, can store any number, any type of mapping type, and

Python built-in functions (24) -- frozenset, pythonfrozenset English document: Class frozenset([ Iterable]) Return a new frozensetObject, optionally with elements taken from Iterable. frozensetIs a built-in class. See

[Terry Notes] python Level 3 menu, Output the Level 3 menu, select it, and display it layer by layer. "B" returns to the level 1 menu. 1 menu = {2 'beijing': {3 'haidian ': {4 'wudaokou': {5 'soho ': {}, 6 'netease ':{}, 7 'Google ': {} 8}, 9