DataFram类型的变量a,设a有n个样本,m个特征,当执行语句b = a.values后,b为(n, m)的ndarray矩阵类型,当执行c = b.ravel()后,c为(n*m,)维行向量…

/*MySQL - 5.5.47 *************//*!40101 SET NAMES utf8 */; create table `base_area` (    `codeid` mediumint (12),    `parentid` int (12),    `cityName` varchar (180)); insert into `base_area` (`codeid`, `parentid`, `cityName`) values('11','0','北京');i…

采集了一下JD的省市区地区 (非常简单,只是做个记录) 1.建表:account_area   2.进入页面: https://reg.jd.com/reg/company 在浏览器(Firefox)控制台(Firebug)上输入:(其他浏览器的控制台也行) var $cr=$(".copyright"); $cr .empty(); function getAreas3(id){ $.get("https://reg.jd.com/reg/area", { lev…

本篇引用以下三个链接: http://www.tgerm.com/2012/01/recordtype-specific-picklist-values.html?m=1 https://github.com/abhinavguptas/Multi-RecordType-Sobject-Picklist-Describer http://bobbuzzard.blogspot.com/2012/01/record-type-picklist-values.html 我们知道,record typ…

Django models .all .values .values_list 几种数据查询结果的对比…

2007/2008 ACM International Collegiate Programming Contest University of Ulm Local Contest Problem F: Frequent values You are given a sequence of n integers a1 , a2 , ... , an in non-decreasing order. In addition to that, you are given several querie…

E - The Values You Can Make Description Pari wants to buy an expensive chocolate from Arya. She has n coins, the value of the i-th coin is ci. The price of the chocolate is k, so Pari will take a subset of her coins with sum equal to k and give it to…

Python’s handling of default parameter values is one of a few things that tends to trip up most new Python programmers (but usually only once). What causes the confusion is the behaviour you get when you use a “mutable” object as a default value; tha…

数据库的在上一篇博客中<SQLite之C语言接口规范(三)——Binding Values To Prepared Statements>用到了如何从查询结果中取出结果值.今天的博客就详细的介绍一下sqlite3_column_*()的方法.在SQLite数据库C语言接口中,从查询结果中取出不同类型的值需要不同的接口函数. 一. sqlite3_column_*()介绍 1.下图是sqlite3_column_*()所包含的方法,由下图容易的看出取出不同类型的值需要不同的接口函数.可以取出的类…

  原因: Pojo类User没提供无参数构造方法, 加上该构造方法后,问题解决 ### Cause: org.apache.ibatis.reflection.ReflectionException: Error instantiating class com.chry.browserServer.db.model.User with invalid types () or values (). cause: java.lang.NoSuchMethodException: com.chry.…