python pandas dataframe

([arr, arr], Axis=1) # Connect two arr, in the direction of the row---------------Pandas-----------------------Ser = series () Ser = series ([...], index=[...]) #一维数组, dictionaries can be converted directly to Seriesser.values ser.index Ser.reindex ([...], fill_value=0) #数组的值, index of array, redefine index ser.isnull () pd.isn Ull (Ser) pd.notnull (Ser) #检测缺失数据ser. name= ser.index.name= #ser本身的名字, ser index name Ser.drop (' x ') #丢弃索引x对应的值ser +ser

Function Prototypes:Https://pandas.pydata.org/pandas-docs/stable/generated/pandas.DataFrame.fillna.html#pandas.DataFrame.fillnaPad/ffill: Fills the missing value with the previous non-missing valueBackfill/bfill: Fills the missing value with the next non-missing valueNone: Specify a value to replace the missing value 123456789101112131415161718192021st22232425262728293031323334353637383940414243444546474849505152535455565758596061 62 63

Pandas has two data structures, one is series and the other is DataframeFrom matplotlib import Pyplot as PltImport NumPy as NPImport Pandas as PDFrom NumPy import nan as NAFrom pandas import DataFrame, Series%matplotlib InlineSeries is essentially a one-dimensional array# Series# arrays are associative to dictionaries,

Array,list,dataframe Index Tile Operation July 19, 2016--smart wave documentA simple discussion on list, one-dimensional, two-dimensional array,datafrme,loc, Iloc and IXNumPy an array of indexes and tiles:Starting with the most basic list index, let's start with a code and result:a = [0,1,2,3,4,5,6,7,8,9] a[:5:-1] #step Output:[9, 8, 7, 6][][1, 0]List slice, in "[]" There are generally two ":" Delimiter, Chinese meaning is [start: End: Step] In the

:00:00 ')2. Time interval# #TimedeltasPD. Timestamp ('9/3/2016')-pd. Timestamp ('9/1/2016')# timedelta (' 2 days 00:00:00 ')PD. Timestamp ('9/2/2016 8:10AM') + PD. Timedelta ('12D 3H')# Timestamp (' 2016-09-14 11:10:00 ') 3. Time in the DataframeDates = Pd.date_range ('10-01-2016', Periods=9, freq='2w-sun') Dates"""Datetimeindex ([' 2016-10-02 ', ' 2016-10-16 ', ' 2016-10-30 ', ' 2016-11-13 ', ' 2016-11-27 ', ' 2016-12-11 ', ' 2016 -12-25 ', ' 2017-01-08 ', ' 2017-01-22 '], dtype= ' datetime64

data conversion refers to filtering, cleaning, and other conversion operations on the data. Remove Duplicate data Repeating rows often appear in the Dataframe, Dataframe provides a duplicated () method to detect whether rows are duplicated, and another drop_duplicates () method to discard duplicate rows:Duplicated () and Drop_duplicates () methods defaultJudging all Columns, if you do not want to, the co

Using XLRD to read ExcelFilter 0 columns with a value greater than 99% and removeImport 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 float (sum)/nrows>=0.99:Del_col.append (j)print Del_col Using Pandas to read ExcelFilter 0 columns with a value greater than

[Spark] [Python] Example of a dataframe in which a limited record is taken:SqlContext = Hivecontext (SC)PEOPLEDF = SqlContext.read.json ("People.json")Peopledf.limit (3). Show ()===[Email protected] ~]$ HDFs dfs-cat People.json{"Name": "Alice", "Pcode": "94304"}{"Name": "Brayden", "age": +, "Pcode": "94304"}{"Name": "Carla", "age": +, "Pcoe": "10036"}{"Name": "Diana", "Age": 46}{"Name": "Etienne", "Pcode":

[Spark] [Python] Dataframe examples of left and right connections$ HDFs Dfs-cat People.json{"Name": "Alice", "Pcode": "94304"}{"Name": "Brayden", "age": +, "Pcode": "94304"}{"Name": "Carla", "age": +, "Pcoe": "10036"}{"Name": "Diana", "Age": 46}{"Name": "Etienne", "Pcode": "94104"}$ HDFs Dfs-cat Pcodes.json{"Pcode": "10036", "City": "New York", "state": "NY"}{"Pcode": "87501", "City": "Santa Fe", "state": "

1 fromPandasImportRead_csv2 3Dataframe = Read_csv (r'URL', nrows = 86400, Usecols = [0,], engine='python')4 #nrows: Read rows, Usecols=[n,]: Read only nth column, Usecols=[a,b,c]: Read A, B, column C5DataSet =dataframe.values6 7List = []8 forKinchDataSet:9 forJinchK:Ten List.append (j) One A Print(Dataframe[0:3]) - Print(Dataset[0:3]) - Print(List[0:3])Get results:FIT101 (attribute name) 0 0.01

, 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

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

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.

One, under Windows (two ways)1. Install the Python edp_free and install the pandas ① If you do not have python2.7 installed, you can directly choose to install the Python edp_free, and then install the pandas and other packages on the line:Python edp_free website: http://epdfree-7-3-2.software.informer.com/7.3/Double

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

Reprint: Original Address http://www.cnblogs.com/lxmhhy/p/6029465.htmlThe recent comparison of a series of data, need to use the NumPy and pandas to calculate, but use Python installation numpy and pandas because the Linux environment has encountered a lot of problems on the network is written down. first, the Python v

Tags: fetchall nbsp python class set for SEL statement RAM (Create connection and cursor code omitted here) SQL1="SELECT * FROM table name" #SQL statement 1Cursor1.execute (SQL1)#Execute SQL statement 1Read1=list (Cursor1.fetchall ())#reading Results 1Sql2="SHOW full COLUMNS from table name" #SQL Statement 2Cursor1.execute (SQL2)#Execute SQL statement 2Read2=list (Cursor1.fetchall ())#assign to variable after reading result 2 and conv

Course Description:??The course style is easy to understand, real case actual cases. Carefully select the real data set as a case, through the Python Data Science library Numpy,pandas,matplot combined with the machine learning Library Scikit-learn to complete some of the column machine learning cases. The course is based on actual combat and all lessons are combined with code to demonstrate how to use these

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