1. In the dataframe of pandas, we often need to select a row for a specified condition based on a property, when the Isin method is particularly effective.
Import Pandas as Pddf = PD. DataFrame ([[1,2,3],[1,3,4],[2,4,3]],index = [' One ', ' both ', ' three '],columns = [' A ', ' B ', ' C ']) print df# A B C # One 1 2 3# 1 3 4# three 2 4 3
Original link: http://www.datastudy.cc/to/69Today, a classmate asked, "Not in the logic, want to use the SQL select c_xxx_s from t1 the left join T2 on T1.key=t2.key where T2.key is NULL logic in Python to implement the Left join (directly with the Join method), but do not know how to implement where key is NULL.In fact, the implementation of the logic of not in, do not be so complex, directly with the Isin function to take the inverse can be, the fol
1. In the dataframe of pandas, we often need to select the rows of a specified condition based on a property, at which point the Isin method is particularly effective.
Import pandas as PD
DF = PD. Dataframe ([[1,2,3],[1,3,4],[2,4,3]],index = [' One ', ' two ', ' three '],columns = [' A ', ' B ', ' C '])
print DF
# A B C
# One 1 2 3
# two 1 3 4
Isin: An advanced filter equivalent to ExcelIsin usage comes in two simple examples:DF = Pd.read_excel (R ' file:///G:/xxx.xlsx ') #总表格Gateway = Pd.read_excel (R ' g:/xxx.xlsx ') #筛选的数据df, gateway are all in Datafram formatDf_gateway = df_1[df_1. Gateway access number. Isin (gateway[' Gateway access number ')] #根据gateway里边的网关接入号筛出df里边的数据的时候If the gateway is not in the Dataframe format, but the listGateway =
This article mainly introduces you to the pandas in Python. Dataframe to exclude specific lines of the method, the text gives a detailed example code, I believe that everyone's understanding and learning has a certain reference value, the need for friends to see together below. When you use Python for data analysis, one of the most frequently used structures is the dataframe of pandas, about
not go to the net.Unique values, value counts, and membership#-*-encoding:utf-8-*-import numpy as Npimport Osimport pandas as Pdfrom pandas import Series,dataframeimport matplotlib. Pyplot as Pltobj = Series ([' A ', ' a ', ' B ', ' f ', ' e ']) uniques = Obj.unique () uniques.sort () #记住这是就地排序 #print uniques# counting statistics, Note that the #print obj.value_counts () #value_counts还是一个顶级的
Python traversal pandas data method summary, python traversal pandas
Preface
Pandas is a python data analysis package that provides a large number of functions and methods for fast and convenient data processing. Pandas defines two data types: Series and DataFrame, which makes data operations easier. Series is a one-di
Pandas basics, pandas
Pandas is a data analysis package built based on Numpy that contains more advanced data structures and tools.
Similar to Numpy, the core is ndarray, and pandas is centered around the two core data structures of Series and DataFrame. Series and DataFrame correspond to one-dimensional sequences and
Pandas Quick Start (3) and pandas Quick Start
This section mainly introduces the Pandas data structure, this article cited URL: https://www.dataquest.io/mission/146/pandas-internals-series
The data used in this article comes from: https://github.com/fivethirtyeight/data/tree/master/fandango
This data mainly describes
']df_obj[' user number '].isin (alist) #将要过滤的数据放入字典中, uses Isin to filter the data, returns the row index and the results of each row filter, and returns if the match is turedf_obj[df_obj[' user number '].isin (alist)] #获取匹配结果为ture的行Filter data using Dataframe blur (like in sql):df_obj[df_obj[' package '].str.contains (R '. * Voice cdma.* ')] #使用正则表达式进行模糊匹配, * m
This article describes how to use the pandas library in Python to analyze cdn logs. It also describes the complete sample code of pandas for cdn log analysis, then we will introduce in detail the relevant content of the pandas library. if you need it, you can refer to it for reference. let's take a look at it. This article describes how to use the
[Data cleansing]-clean "dirty" data in Pandas (3) and clean pandasPreview Data
This time, we use Artworks.csv, And we select 100 rows of data to complete this content. Procedure:
DataFrame is the built-in data display structure of Pandas, and the display speed is very fast. With DataFrame, we can quickly preview and analyze data. The Code is as follows:
import pandas
This article describes how to use the pandas library in Python to analyze cdn logs. It also describes the complete sample code of pandas for cdn log analysis, then we will introduce in detail the relevant content of the pandas library. if you need it, you can refer to it for reference. let's take a look at it.
Preface
A requirement encountered in recent work is
Pandas data analysis (data structure) and pandas Data Analysis
This article mainly expands pandas data structures in the following two directions: Series and DataFrame (corresponding to one-dimensional arrays and two-dimensional arrays in Series and numpy)
1. First, we will introduce how to create a Series.
1) A sequence can be created using an array.
For example
Data analysis and presentation-Pandas data feature analysis and data analysis pandasSequence of Pandas data feature analysis data
The basic statistics (including sorting), distribution/accumulative statistics, and data features (correlation, periodicity, etc.) can be obtained through summarization (lossy process of extracting data features), data mining (Knowledge formation ).
The. sort_index () method so
Teach you how to use Pandas pivot tables to process data (with learning materials) and pandas learning materials
Source: bole online-PyPer
Total2203 words,Read5Minutes.This article mainly explains pandas's pivot_table function and teaches you how to use it for data analysis.
Introduction
Most people may have experience using pivot tables in Excel. In fact, Pandas
The pandas Series is much more powerful than the numpy array , in many waysFirst, the pandas Series has some methods, such as:The describe method can give some analysis data of Series :Import= PD. Series ([1,2,3,4]) d = s.describe ()Print (d)Count 4.000000mean 2.500000std 1.290994min 1.00000025% 1.75000050% 2.50000075% 3.250000max 4.000000dtype:float64Second, the bigges
The previous Pandas array (Pandas Series)-(3) Vectorization, said that when the two Pandas series were vectorized, if a key index was only in one of the series , the result of the calculation is nan , so what is the way to deal with nan ?1. Dropna () method:This method discards all values that are the result of NaN , which is equivalent to calculating only the va
Sometimes you need to do some work on the values in the Pandas series , but without the built-in functions, you can write a function yourself, using the Pandas series 's apply method, You can call this function on each value inside, and then return a new SeriesImport= PD. Series ([1, 2, 3, 4, 5])def add_one (x): return x + 1print s.apply ( Add_one)# results:0 6dtype:int64A chestnut:Names =PD. Serie
Data conversionDelete duplicate elements The duplicated () function of the Dataframe object can be used to detect duplicate rows and return a series object with the Boolean type. Each element pairsshould be a row, if the row repeats with other rows (that is, the row is not the first occurrence), the element is true, and if it is not repeated with the preceding, the metaThe vegetarian is false.A Series object that returns an element as a Boolean is of great use and is particularly useful for fil
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