each

From perldoc -f each we read: There is a single iterator for each hash, shared by all each , keys , and values function calls in the program; it can be reset by reading all the elements from the hash, or by evaluating keys HASH or values HASH . The iterator is not reset when you leave the scope containing the each() , and this can lead to bugs: my %h = map { $_, 1 } qw(1 2 3); while (my $k = each %h) { print "1: $k\n"; last } while (my $k = each %h) { print "2: $k\n" } Output: 1: 1 2: 3 2: 2 What are the common workarounds for this behavior? And is it worth using each in general? draegtun I

网易云音乐核心功能是其推荐算法，据观察，日推主要采用itemCF方法。网易云音乐根据每日获取到的听歌列表，优先推荐跟该歌曲相似的歌曲。如今，网易云音乐着重社交功能，因此，本文尝试构建基于用户的推荐系统。 摘要： 本文思路是根据用户 所有时间 听歌排行计算相似度，推荐用户 最近一周 听歌次数大于2次的歌曲。采用jaccard距离和向量余弦计算相似度。本文目录为数据集获取、数据预处理、数据分析、算法实现和结果输出 一、数据集获取 分析网易云音乐听歌排行页面发现最近一周数据和所有时间数据是动态加载，因此使用requests+beautifulsoup很难获得完整的数据。 进一步分析网页源代码，点击network，选择XHR，重新加载网页，我们在最后一个文件中找到我们要的数据，下图的preview为json文件，点击headers可以看到，浏览器是使用post方法请求json数据，因此我们的爬虫也使用post方法 上代码 import json from urllib import request, parse headers = { 'User-Agent': 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.99 Safari/537.36' }

一 基础了解 对应关系 -> https://docs.mongodb.com/manual/reference/sql-comparison/ database -> database collection -> table document -> row //无模式 field -> column -------------------------------------------------------------------------------------- 使用数据库 use 数据库名称 创建数据库并创建集合myNewCollection1插入数据 use myNewDB db.myNewCollection1.insertOne( { x: 1 } ) -------------------------------------------------------------------------------------- 创建集合并插入数据 db.myNewCollection22.insertOne( { xxx: 1 } ) 固定大小集合 capped collection 先进先出 创建一个集合x1 是上限集合,大小200字节 最大2个document,先进先出 也可以不指定document大小db.createCollection("x1", {

I work with single file components and have a list in one of them. This list should work like a accordion, but as far as I can find in the Vuejs docs, it's not that easy to make each item open separately very easily. The data (questions and answers) is retrieved from an ajax call. I use jQuery for that, but would like to know how I can make the accordion work Vuejs-style. Any help would be appreciated! Here's the code: export default { name: 'faq-component', props: ['faqid', 'faqserviceurl', 'ctx'], data: function () { return { showFaq: "", totalFaqs: this.data, isOpen: true } }, watch: {

I want to add some HTML elements that have the same class name. So, the code will be like this with jQuery. $(".force").each(function (){ a += parseInt( $(this).html()); }); $("#total_forces").html(a); In this code, the variable has to be global. Is there any other elegant way to sum every .force value and get the sum out of the each function without global variable? If you don't want to introduce a global variable, you could use something like this: $("#total_forces").html(function() { var a = 0; $(".force").each(function() { a += parseInt($(this).html()); }); return a; }); user113716 For

对一个网站挖掘的深浅来说就得看你收集的如何，这说明信息收集在漏洞挖掘中是非常的重要的。 子域名收集 子域名收集是最简单的收集手法之一，有很多在线的工具可以直接套用，这里分享几个我经常用的。 开心的时候用用这个扫描器 为什么这么说，因为这是我写的（你生气用的话我怕我屏幕里突然冒出一个拖孩） 1 import requests 2 import threading 3 from bs4 import BeautifulSoup 4 import re 5 import time 6 7 url = input( 'url(如baidu.com): ' ) 8 9 head={'User-Agent':'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36 SE 2.X MetaSr 1.0'} 10 11 ip = 'http://site.ip138.com/{}'.format( url ) 12 # domain_url = url.split('.') 13 # domain_url = domain_url[1]+'.'+domain_url[2] 14 domain_url = url 15 domain =

I have a function which get a dot seperated string and parse it to array. And I want to loop these array elements and check a value is greater than 255 and return false, if not continue to function statements and return true as end of function. But it never stops the loop.. and always return true. Here is code: checkipAddress = function(value){//instance value: 999.999.999.999 result:true debugger var array = value.split('.'); $.each(array, function(index,val){ debugger if(parseInt(val)>255) return false; // it should end the loop and exit function with return false. }); return true; }