Pandas. DataFrame
pandas. class
DataFrame
(data=none, index=none, columns=none, dtype=none, copy=false) [Source]
Two-dimensional size-mutable, potentially heterogeneous tabular data structure with labeled axes (rows and columns). Arithmetic operations align on both row and
This time to bring you pandas in the Dataframe query what methods, pandas in the Dataframe query of what matters, the following is the actual case, together to see.
Pandas provides us with a variety of slicing methods, which are often confusing if you don't know them well.
Pandas (python) data processing: only the DataFrame data of a certain column is normalized.
Pandas is used to process data, but it has never been learned. I do not know whether a method call is directly normalized for a column. I figured it out myself. It seems quite troublesome.
After reading the Array Using Pandas,
[Python logging] importing Pandas Dataframe into Sqlite3 and dataframesqlite3
Use pandas. io connector to input Sqlite
Import sqlite3 as litefrom pandas. io import sqlimport pandas as pd
According to if_exists, input sqlite in three modes:
The following parameters are av
This article mainly gives you a detailed explanation of python in pandas. Dataframe exclude specific Line Method sample code, the text gives the detailed sample code, I believe that everyone's understanding and learning has a certain reference value, the need for friends to see together below.
Pandas. Dataframe Exclud
Using Python for data analysis (7)-pandas (Series and DataFrame), pandasdataframe 1. What is pandas? Pandas is a Python data analysis package based on NumPy for data analysis. It provides a large number of advanced data structures and data processing methods. Pandas has two
Pandas series DataFrame row and column data filtering, pandasdataframe
I. Cognition of DataFrame DataFrame is essentially a row (index) column index + multiple columns of data.
To simplify our understanding, let's change our thinking...
In reality, to simplify the description of a thing, We will select several feature
Let's create a data frame by hand.[Python]View PlainCopy
Import NumPy as NP
Import Pandas as PD
DF = PD. DataFrame (Np.arange (0,2). Reshape (3), columns=list (' abc ' )
DF is such a dropSo how do you choose the three ways to pick the data?One, when each column already has column name, with DF [' a '] can choose to take out a whole column of data. If you know column names and index
already has column name, use data [' col1 '] to choose to take out an entire column of data. If you know column names and index, you can choose. loc simultaneously row and column selection: Data.loc[index, ' colum_names '] iloc functionUse the method with the LOC function, but no longer enter the column name, but the index:data.iloc[row_index,col_index of the input column]The functions of the IX function IX are more powerful, and the parameters can be either an index or a name, equivalent to th
1. Create a dataframe from a dictionary>>>ImportPandas as PD>>> Dict1 = {'col1': [1,2,5,7],'col2':['a','b','C','D']}>>> DF =PD. DataFrame (Dict1)>>>DF col1 COL201a1 2b2 5C3 7 D2. Create Dataframe from multiple lists (convert the list to a dictionary, then convert the dictionary to dataframe)>>> lista = [1,2,5,7]>>> LIS
1. Create a dataframe from a dictionary>>>ImportPandas>>> dict_a = {'user_id':['Webbang','Webbang','Webbang'],'book_id':['3713327','4074636','26873486'],'rating':['4','4','4'],'mark_date':['2017-03-07','2017-03-07','2017-03-07']}>>> df = Pandas. DataFrame (DICT_A)#Create a dataframe from a dictionary>>> DF#The created
Today, I want to pandas in the row of the operation, looking for a long time to find the relevant functions
First look at a small example
From pandas import Series, dataframe
data = Dataframe ({' K ': [1, 1, 2, 2]})
print data
isduplicated = DATA.DUPL icated ()
print isduplicated
print type (isduplicated)
da
Dataframe. drop_duplicates (subset = none, keep = 'first', inplace = false)
SubsetTo determine which column duplicate occurs, all columns are considered by default.KeepContains three parametersFirst,Last,False,FirstIt indicates that the first repeat data retrieved is retained and all subsequent data are deleted;LastIndicates that the last retrieved duplicate data is retained and all previously searched duplicate data is deleted,FalseThis means that a
Ming 6.0 - Name:price, Dtype:float64 -Zhang San 1.2 theReese 1.0 -Harry 2.3 -Chen Jiu 5.0 -Xiao Ming 6.0 +Name:price, Dtype:float64 In general, we often need to value by column, then Dataframe provides loc and Iloc for everyone to choose from, but the difference is between the two.1 Print(frame2)2 Print(frame2.loc['Harry'])#Loc can use the index of the string type, whereas the Iloc can only be of type int3 Print(frame0.iloc[2])4 out[2]: 5 Color Obje
The processing of the data is pandas, but it has not been learned and does not know whether there is a method call that is directly normalized to a column. Himself dealing things down. The feeling is still more troublesome.After reading to the array using pandas, I want to have the ' monthlyincome ' column normalized, and the chestnuts on the web are normalized to the entire
This section describes the basic methods of data in series and Dataframe
Re-index
An important method of Pandas objects is reindex, which is to create a new object that adapts to the new index" "Created on 2016-8-10@author:xuzhengzhu" "" "Created on 2016-8-10@author:xuzhengzhu" " fromPandasImport*Print "--------------obj Result:-----------------"obj=series ([4.5,7.2,-5.3,3.6],index=['D','b',
Import NumPy as NP from
Pandas import dataframe
import pandas as PD
Df=dataframe (Np.arange () reshape (3,4 ), index=[' One ', ' two ', ' THR '],columns=list (' ABCD ')
df[' A ' #取a列
df[[' A ', ' B ']] #取a, column B
#ix可以用数字索引, You can also use index and column indexes
df.ix[0] #取第0行
df.ix[0:1] #取第0行
df.ix[' one ':
I believe many people like me in the process of learning Python,pandas data selection and modification has a great deal of confusion (perhaps by the Matlab) impact ...
To this day finally completely figure out ...
Let's start with a data box manually.
Import NumPy as NP
import pandas as PD
DF = PD. Dataframe (Np.arange (0,60,2). Reshape (10,3), columns=list (' a
', DF ['v1']) #2 indicates the insert position, and V6 indicates the column name, DF ['v1 '] is the inserted value print ('insert column:') print (DF, '\ n') print (' * 50)
4. General selection methods:
Operation Method
Method
Result
Select a column
Def [col]
Sequence
Select a row using column tags
DF. Loc [col]
Sequence
Select a row by location
DF. icol [2]
Sequence
Line Cutting
DF [5: 10]
Data box
Label:Read the contents of the table, as in the following example: ImportMySQLdbTry: Conn= MySQLdb.connect (host='127.0.0.1', user='Root', passwd='Root', db='MyDB', port=3306) DF= Pd.read_sql ('select * from test;', con=conn) Conn.close ()Print "Finish Load DB"
exceptmysqldb.error,e:PrintE.ARGS[1] Write the data to the table, as in the following example DF = PD. DataFrame ([[1,'XXX'],[2,'yyy']],columns=list ('AB'))
Try: Conn= MySQLdb.connect (host='1
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