pivot | 易学教程

How do you “pivot” using conditions, aggregation, and concatenation in Pandas?

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问题 I have a dataframe in a format such as the following: Index Name Fruit Quantity 0 John Apple Red 10 1 John Apple Green 5 2 John Orange Cali 12 3 Jane Apple Red 10 4 Jane Apple Green 5 5 Jane Orange Cali 18 6 Jane Orange Spain 2 I need to turn it into a dataframe such as this: Index Name All Fruits Apples Total Oranges Total 0 John Apple Red, Apple Green, Orange Cali 15 12 1 Jane Apple Red, Apple Green, Orange Cali, Orange Spain 15 20 Question is how do I do this? I have looked at the groupby

Laravel 3 way intermediate pivot table

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问题 I am having trouble defining the relationships in my Eloquent Models when using a 3 way intermediate pivot table. Here are the 4 tables in my database: users - id - name instruments - id - key instruments_users - id - user_id - instrument_id - level_id levels - id - key Instruments keys can be: guitare , piano , trumpet , etc. Levels keys can be: beginner , intermediate , expert , etc. Each user can play of 1 or more instrument. For each played instrument (relationship), we attribute a level

Laravel 3 way intermediate pivot table

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SQL pivot data with dynamic list of columns

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问题 Im stuck on a particular problem im hoping someone can help me out with. I have four tables Product, ProductType, Orders. I want to view Data from the Orders table but want to view it in a way where on each day the data is grouped by the sum of product quantity sold for each day under each ProductType. Please view the table structure, I have tried to get the Product groups as an array list and am able to sum the product quantity up for each product type group but cant figure out how to view

SQL Server 2016 Pivot

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问题 I have one question regarding sql (MS SQL 2016) and pivot functionality. First let me explain about the data structure. Examples of tbl_Preise . There are several prices ( Preis ) for each area ( Gebiet_von , Gebiet_bis ) in relays ( StaffelNr ). All connected to the same freight ( Fracht_id ). There can be a different number of relays for each freight. All of these relays repeat for each area, so i.e. there is one price for relay 1 in area 1800 - 1899 , but there is another price for relay 1

control flow for calling other columns in function

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问题 I'm trying to make a connection to other columns within a function given a conditional. Essentially, I want to make a dataframe go from long to wide given a conditional, where those values in one column are NA relative to another column that has values in that same row, turn the NAs into a specific numeric. Although the values assigned have to be column specific. So if 2010 has NAs whilst 2019 has a value, then return 16 otherwise, if 2019 has NAs when in that same row, 2010 has values,

PostgreSQL query with dynamic number of columns

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问题 I am trying to find a method to return a record set with a dynamic number of columns. I can write one query that will produce the list of column names I need as such: SELECT DISTINCT name FROM tests WHERE group = 'basic'; This will return a short list like 'poke', 'prod', 'hit', 'drop', etc. Then I want a table produced showing a series of tests where each of those tests were run. Every morning we look at what the developers have been doing and poke and prod at it so each test will be run for

pandas groupby transpose str column

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问题 here is what I am trying to do: >>>import pandas as pd >>>dftemp = pd.DataFrame({'a': [1] * 3 + [2] * 3, 'b': 'a a b c d e'.split()}) a b 0 1 a 1 1 a 2 1 b 3 2 c 4 2 d 5 2 e 6 3 f how to transpose column 'b' grouped by column 'a', so that output looks like: a b0 b1 b2 0 1 a a b 3 2 c d e 6 3 f NaN NaN 回答1: Using pivot_table with cumcount : (df.assign(flag=df.groupby('a').b.cumcount()) .pivot_table(index='a', columns='flag', values='b', aggfunc='first') .add_prefix('B')) flag B0 B1 B2 a 1 a a

How to pass data from C++ application to Javascript

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问题 I'm developing a jQuery-based pivot table. The goal is not a web app but a desktop-based application (C++). In my idea, data is retrieved by the application from the database, then passed to a html page and then showed through the pivot-table plugin. There is no web server and the web page containing the plugin cannot access to the database. So, how to pass data in an efficient way? I've seen other questions here on SO around this matter, but I think we're in a different scenario. Of course I

微软发布了免费的文件恢复工具！

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误删文件这事相信大家都碰到过，比如不小心误删了一个重要的文件，一不留神就把自己的硬盘清空了，或者是面对已经被误删的文件手足无措......以前碰到这种情况，有实力的程序员们就靠实力恢复误删的文件，像猿妹这样没实力的，网上购买个小工具也可以帮我恢复，就是费钱。现在好了，最近微软在 Windows 10 应用商店中上架了一款免费的数据删除恢复工具 Windows File Recovery，猿妹再也不用担心误删文件了。 Windows File Recovery基于命令行程序设计，大小仅有8.26MB，所有Windows 10用户均可免费下载使用。无论是照片、文档、视频还是其他，Windows File Recovery都可以帮你恢复，而且它还支持机械硬盘、固态硬盘、U盘、SD卡等多种硬件类型，遗憾的是，不支持网络驱动器文件恢复。下面还是一起来看看用法吧：嵌入式专栏 1 下载安装首先，通过下载链接打开“Windows File Recovery”的下载界面，点击“获取”按钮安装。（下载地址：https://www.microsoft.com/zh-cn/p/windows-file-recovery/9n26s50ln705?activetab=pivot:overviewtab）这里需要提醒大家的是，安装Windows File Recovery操作系统要求Windows