[Spring Boot] Mybatis Plus 3.X condition query

[introduction] I wrote a blog before< [Spring Boot] Mybatis Plus 2.X condition query >, we know that the query methods of Mybatis Plus 2.X and 3.X are not the same. This blog will summarize the application of various query methods of 3.X. [example] Take the query of article table as an example to ...

Added by zampu on Tue, 17 Mar 2020 10:32:01 +0200

pandas advanced use group aggregation

Article directory Grouping and aggregation 1. GroupBy object ·Parameters in the groupedby function: GroupBy object group iteration = = = "traversal" Other grouping methods polymerization Grouping operation Group and align Statistical calculation yao differential aggregation aggreg ...

Added by JCF22Lyoko on Fri, 13 Mar 2020 14:49:33 +0200

New features of Java 8 -- Lambda expression

New features of Java 8 -- Lambda expression Before Java 8, we wanted a method to interact with the user, such as using local variables within the method. At this time, we can only use the interface as a parameter, so that the user can implement the interface or use the form of anonymous inner class t ...

Added by Tea_J on Wed, 11 Mar 2020 13:20:46 +0200

C × lambda expression

In versions of C before 2.0, the only way to declare a delegate was to use a named method. C ා 2.0 introduces anonymous methods, while in C ා 3.0 and later, Lambda expressions replace anonymous methods as the preferred way to write inline code. In one case, anonymous methods provide functionality tha ...

Added by mars_rahul on Mon, 09 Mar 2020 11:20:43 +0200

Python 3 Standard Library: Tools for functools to manage functions

1. Tools for functools to manage functions The functools module provides tools to adjust or extend functions and other callable objects without requiring a complete override. 1.1 Modifier The main tool provided by the functools module is the partial class, which can be used to "wrap" a callable object with default parameters.The resul ...

Added by wkrauss on Thu, 27 Feb 2020 04:13:47 +0200

Task 07: advanced optimization algorithm; word2vec; advanced word embedding

Task07: advanced optimization algorithm; word2vec; advanced word embedding 1. Advanced optimization algorithm Momentum In Section 11.4, we mentioned that the gradient of the objective function with respect to the independent variable represents the direction in which the objective function declines ...

Added by n14charlie on Tue, 25 Feb 2020 08:47:29 +0200

Attention Mechanism and Seq2seq Model of Tak04-2 Attention Camp for DataWhale Group

Attention mechanism In section Encoder-Decoder (seq2seq), the decoder relies on the same context vector to obtain input sequence information at each time step.When the encoder is a circular nerve network, the background variable comes to the hidden state of its final time step.The source sequence inpu ...

Added by FezEvils on Wed, 19 Feb 2020 05:38:48 +0200

java8 stream interface terminal operation collect operation

Before that, we talked about the stream operation in java8, which is divided into intermediate operation and terminal operation. In terminal operation, we also saw the reduction mode. This article mainly refers to the reduction operation mode collection, collector operation and collector operation, which can be regarded as a mo ...

Added by Reviresco on Thu, 13 Feb 2020 22:34:28 +0200

tensorflow tutorial begins - dataset: get to know tf.data quickly

Reference article: datasets: quick learn Datasets: quick learn tf.data Read memory data from the numpy array. Read the csv file line by line. Basic input Learning how to get array fragments is the easiest way to start learning tf.data. Premade Estimators def train_input_fn(features, labels, batch_ ...

Added by herando on Tue, 11 Feb 2020 10:51:25 +0200

Pyspark learning -- 2. Try to run pyspark

pyspark learning -- 2. pyspark's running method attempt and various sample code attempts Operation method Pycharmrun spark operation in the system: spark submit Start spark task run Sample code Streaming text processing streaming context Stream text word count Error reporting summary Operati ...

Added by lemming_ie on Sat, 08 Feb 2020 10:38:57 +0200