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brief introduction The content is long, suitable for collection and learning. This content contains all knowledge points and grammar. Friends who like it can collect it for future learning. Python is a high-level scripting language that combines interpretability, compilation, interactivity and object-oriented. Python was invented by Guido van ...

Section I data cleaning and feature processing View missing values in dataset Use isnull() or isna(), or info() to view the number of non empty data in the dataset Here are some pits: NP in numpy Nan is in float format and cannot judge two NP The number of Nan is equalNone is a NoneType, NP The result of Nan is none will also be FalseThe ...

1 Introduction Similarity and dissimilarity are important concepts in machine learning, because they are adopted by many data mining technologies, such as common clustering, nearest neighbor classification and anomaly detection. In many cases, once we calculate the similarity or dissimilarity of eigenvectors, we no longer need the original dat ...

reference material: https://gitee.com/datawhalechina/hands-on-data-analysis Chapter 3 model building and evaluation - Modeling After learning the knowledge points in the previous two chapters, I can process the data itself, such as adding, deleting, checking and supplementing the data itself, and do the necessary cleaning work. Then we'll sta ...

Data consolidation Common data consolidation methods for pandas: pandas.merge connects rows in different DataFrame s based on one or more keys, which is the join operation of the database.pandas.concat can stack multiple objects together along an axisInstance method combine_first can stitch together duplicate data and fill in missing valu ...

To analyze whether there are excess deaths in the cohort, the standard population mortality is usually used to correct. The actual number of deaths (d) in the immediate observation and a standard number of deaths (E). The ratio of D to e is called the standardized mortality ratio (SMR). The standardized mortality rate (SMR) is the ratio of obse ...

​ Database benefits 1.Persistent data to local 2.It can realize structured query and facilitate management Database related concepts 1,DB: Database, a container that holds a set of organized data 2,DBMS: Database management system, also known as database software (product), is used for management DB Data in 3,SQL:Structured query langu ...

Official account: Special HouseAuthor: PeterEditor: Peter Hello, I'm Peter~ This article introduces the four row column conversion methods in Pandas, including: melttranspose T or transferwide_to_longexplode (explosion function) Finally, answer a data processing question asked by a reader friend. Pandas row column conversion There a ...

Project introductionBuilding block report, a free Visual Web Report tool, online drag and drop design like building blocks! Functions include data report, print design, chart report, large screen design, etc!Adhering to the product concept of "simple, easy-to-use and professional", it greatly reduces the difficulty of report developme ...

In this section, we will learn more about List operations in more detail! 1, What is the list? What a list is: a box can hold all kinds of things, and the box is equivalent to this list, which is what can hold all kinds of data in the program. To put it professionally, a list is composed of a series of elements arranged in a specific order. ...