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Merge (): Pay attention to using merge or join # merge is because two merged objects have the same columns, and merge merges with these same columns as indexes. Merge by index, two sorce s will appear, not join # join implements index-by-index merging regardless of whether they have the same columns. At the same time, you can ...

Flow (IO stream): input-output-stream. Function: To achieve communication between two devices. Devices: Memory, Hard Disk, Console, Keyboard, File, Network Network: On the network, outside of your host environment. Classification of flows: Classification by operation: input stream and output stream Classification ...

Kernel Support Vector Machine The important parameters of kernel SVM are regularization parameter C, selection of kernel and parameters related to kernel. It performs well in low-dimensional data and high-dimensional data. But the scaling of sample size is not good. Preprocessing data and parameterization require great care. ...

Baidu Encyclopedia Eclipse is open source code Based on Java Extensible development platform. In itself, it is just a framework and a set of services for building development environments through plug-in components. Fortunately, Eclipse comes with a standard set of plug-ins, including Java development tool(Java Development Kit ...

Python crawls the novel of the New Pen Fun Pavilion and saves it in the TXT file This article I wrote is a program written by Python crawling fiction, which is the first program I wrote independently among Python crawlers. I also encountered some difficulties in the middle, but finally solved it. This program is very simple, t ...

There are many ways to install kafka: 1. Single-machine mode (divided into windows mode; linux mode); 2. Pseudo-distributed mode; 3. Distributed mode; Specific building methods for reference: https://blog.csdn.net/xlgen157387/article/details/77312569?utm_source=blogxgwz0 The following is the stand-alone mode under Linux: 1. In ...

There are two ways to read HBase. One is to inherit RichSourceFunction, rewrite the parent method, and the other is to implement the OutputFormat interface. The code is as follows: Way 1: Inherit RichSourceFunction package com.my.flink.utils.streaming.hbase; import com.my.flink.utils.config.ConfigKeys; import org.apache.flin ...

PyQuery is a powerful and flexible web parsing library in python. If you find regular writing too cumbersome and Beautiful Soup grammar too difficult to remember, if you are familiar with jQuery grammar, PyQuery is your best choice. Installation: pip3 install pyquery I. Initialization Here are three ways to initialize PyQuery. ...

Execution sequence from:Which datasheet do you need to retrieve data from? where:Conditions of data in filter tables group by:How to group the filtered data above having:Conditions for filtering data grouped above select:View which column in the result set, or the result of the column calculation order by :In what order do yo ...

Cause, when using mirror-maker to test cluster copy data from production cluster top, the error is as follows: [2018-10-23 10:21:47,821] FATAL [mirrormaker-thread-2] Mirror maker thread failure due to  (kafka.tools.MirrorMaker$MirrorMakerThread) java.util.concurrent.ExecutionException: org.apache.kafka.common.errors.TimeoutEx ...