Sometimes we can rank and sort series and dataframe based on the size of the index or the size of the value. A, sorting
Pandas provides a Sort_index method that sorts A, series sort 1, sorted by index based on the index of rows or columns in the order of the dictionary.
#定义一个Series
s = Series ([1,2,3],index=["A", "C", "B"])
#对Series的索引进行排序, the default is ascending
print (S.sort_index ())
pandas import Series,dataf The Rame#numpy element progression group method also applies to pandas object frame = DataFrame (Np.random.randn (4,3), columns = List (' abc '), index = [' Ut ', ' Oh ', ' Te ', ' Or ']) print frame# The following is the absolute value: #print Np.abs (frame) #另一种常见的做法是: Apply a function to a row or column, using the Apply method, like the R language fun = Lambda X:x.max ()-X.min
select to rank by row or column. Currently, it seems that there is no ranking method for all elements.Statistical methods
Pandas objects have some statistical methods. Most of them belong to reduction and summary statistics, which are used to extract a single value from Series or extract a Series from a row or column of DataFrame.
For exampleDataFrame.mean(axis=0,skipna=True)Method. When there are NA value
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
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
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
[Data analysis tool] Pandas function introduction (I), data analysis pandas
If you are using Pandas (Python Data Analysis Library), the following will certainly help you.
First, we will introduce some simple concepts.
DataFrame: row and column data, similar to sheet in Excel or a relational database table
Series: Single Column data
Axis: 0: Row, 1: Column
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
[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
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
, how to do? For more information please go to other blogs, where more detailed instructions are available .Pandas import time data for format conversion Draw multiple graphs on one canvas and add legends1 fromMatplotlib.font_managerImportfontproperties2Font = fontproperties (fname=r"C:\windows\fonts\STKAITI. TTF", size=14)3colors = ["Red","Green"]#the color used to specify the line4Labels = ["Jingdong","12306"]#used to specify the legend5Plt.plot (
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
This article describes how the pandas series with the index index is vectorized:1. Index indexed arrays are the same:S1 = PD. Series ([1, 2, 3, 4], index=['a','b','C','D']) S2= PD. Series ([ten, +, +], index=['a','b','C','D'])PrintS1 +s2a11b22C33D44Dtype:int64Add the values corresponding to each index directly2. Index indexed array values are the same, in different order:S1 = PD. Series ([1, 2, 3, 4], index=['a','b','C','D']) S2= PD. Series ([ten, +,
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
1.rank function
Rank calculates the rank of a set of values and returns the numeric type. Rankings may be discontinuous. If there are 5 people, 2 of whom rank first, then rank returns the result: 1 1 3 4 5. As an aggregate function, returns the
0d 3dtype:int64> >> Ser.rank () a 3.5b 2.0c 1.0d 3.5dtype:float64>>> ser.rank (method= ' min ') a 3b 2c 1d 3dtype:float64>>> ser.rank (method= ' Max ') a 4b 2c 1d 4dtype : Float64>>> Ser.rank (method= ' first ') a 3b 2c 1d 4dtype:float64Note that the different method parameters show different positions on the ser[0]=ser[3.The DataFrame .rank(axis=0, method=‘average‘, ascending=True) method has a n
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