python pandas dataframe join

Hierarchical Indexes Hierarchical indexing means you can have multiple indexes on an array, for example: a bit like a merged cell in Excel, right?Select a subset of the data based on the index to select a subset of the data from the other layer:Select data in the same way as the index in the layer:Multi-index series conversion to Dataframe hierarchical indexes play an important role in data reshaping and grouping, for example, the hierarchical index d

, 164.000000f, 159.000000f, 157.000000f, 145.000000f, 135.000000f, 120.000000f, 104.000000f, 88.000000f, 77.000000f, Surface Chart Scripts # -*- coding: utf-8 -*-from matplotlib import pyplot as pltfrom mpl_toolkits.mplot3d import Axes3Dfrom pandas import DataFramedef draw(x, y, z):‘‘‘采用matplolib绘制曲面图:param x: x轴坐标数组:param y: y轴坐标数组:param z: z轴坐标数组:return:‘‘‘X = xY = yZ = zfig = plt.figure()ax = fig.add_subplot(111, projection=‘3d

From OPENPYXL import load_workbook import pandas as PDdata = Pd.read_excel (' test1.xlsx ', sheetname=0) # col_data = List (data.ix[:, 5]) # Gets the fifth column that starts outside the header Row_data = List (data.ix [5,:]) # Gets the fifth row of data except the header starting with writer = PD. Excelwriter (' test2.xlsx ', engine= ' OPENPYXL ') book = Load_workbook (' test2.xlsx ') writer.book = Book result = PD.

the unique value of A, the number of occurrences (a, b) of the unique value of statistics = (1,3) c appears 1 times (A, B) = (2,4) appears 3 times - the Print(Pd.crosstab (df['A'],df['B'],normalize=true))#display in a frequency-based manner - Print('--------') - Print(Pd.crosstab (df['A'],df['B'],values=df['C'],aggfunc=np.sum))#values: A value array based on a factor aggregation - #Aggfunc: If the values array is not passed, the frequency table is computed, and if the array is passed, the calc

Python uses pandas and xlrd to read excel files, feature filtering columns, and pandasxlrd Use xlrd to read excelFilter and delete columns with 0 values over 99%.Import xlrdWorkbook = xlrd. open_workbook (R "123.xlsx ")Table = workbook. sheet_by_name ('Sheet1 ')Nrows = table. nrowsNcols = table. ncolsDel_col = []For j in range (ncols ):Sum = 0For ai in table. col_values (j ):If ai = 0.0:Sum + = 1If

Excel has a computational function skew () for skewness, but it is unclear how to traverse with Excel, which has a large amount of data.Try using Python for resolution.The first time to learn python, did not expect to overcome the installation of various packages of sadness, incredibly successful implementation.python3.3:#this is a test case#-*-coding:gbk-*-print ("Hello

1.1. Pandas Analysis steps Loading data COUNT the date of the access_time. SQL similar to the following: SELECT date_format (access_time, '%H '), COUNT (*) from log GROUP by Date_format (access_time, '%H '); 1.2. Code Cat pd_ng_log_stat.py#!/usr/bin/env python#-*-Coding:utf-8-*-From Ng_line_parser import NglineparserImport Pandas as PDImport socketImport str

Use Python for data analysis _ Pandas _ basic _ 2, _ pandas_2Reindex method of Series reindex In [15]: obj = Series([3,2,5,7,6,9,0,1,4,8],index=['a','b','c','d','e','f','g', ...: 'h','i','j'])In [16]: obj1 = obj.reindex(['a','b','c','d','e','f','g','h','i','j','k'])In [17]: obj1Out[17]:a 3.0b 2.0c 5.0d 7.0e 6.0f 9.0g 0.0h 1.0i 4.0j 8.0k NaNdtype: float64 If the current va

For example we have the dataframe like this: SPY AAPL IBM GOOG GLD2017-01-03 222.073914 114.311760 160.947433 786.140015 110.4700012017-01-04 223.395081 114.183815 162.940125 786.900024 110.8600012017-01-05 223.217606 114.764473 162.401047 794.020020 112.5800022017-01-06 224.016220 116.043915 163.200043 806.150024 111.7500002017-01-09 223.276779 117.106812 161.390244 806.650024 1

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the string object method Split () method splits the string:The Strip () method removes whitespace and line breaks:Split () in combination with strip () using:The "+" symbol allows you to concatenate multiple strings together:The join () method is also the connection string, comparing it to the "+" symbol:The In keyword determines whether a string is contained in another string:The index () method and the Find () method determine the location of a su

1 ImportPandas as PD2DF1 = PD. DataFrame ([[1,2,3],[5,6,7],[3,9,0],[8,0,3]],columns=['X1','X2','X3'])3DF2 = PD. DataFrame ([[1,2],[4,6],[3,9]],columns=['X1','X4'])4 Print(DF1)5 Print(DF2)6DF3 = Pd.merge (df1,df2,how =' Left', on='X1')7 Print(DF3)8DF4 = Pd.merge (df1,df2,how =' Right', on='X1')9 Print(DF4)TenDf5 = Pd.merge (df1,df2,how ='Inner', on='X1') One Print(DF5) ADf6 = Pd.merge (df1,df2,how ='outer',

This article brings the content is about Python pandas in-depth understanding (code example), there is a certain reference value, the need for friends can refer to, I hope to help you. First, screening First, create a 6X4 matrix data. Dates = Pd.date_range (' 20180830 ', periods=6) df = PD. DataFrame (Np.arange) reshape ((6,4)), index=dates, columns=[' A ', ' B

ImportOSImportPandas as PDImportMatplotlib.pyplot as PltdefTest_run (): start_date='2017-01-01'End_data='2017-12-15'dates=Pd.date_range (start_date, End_data)#Create an empty data frameDF=PD. DataFrame (index=dates) Symbols=['SPY','AAPL','IBM','GOOG','GLD'] forSymbolinchsymbols:temp=getadjcloseforsymbol (symbol) DF=df.join (temp, how='Inner') returnDF def Normalize_data (DF): "" " normalize stock prices using the first row of the DATAFR Ame