阿里巴巴AI - Pandas

Pandas的两个主要数据结构

1.Series - 主要用于处理一维数据,一般由一个数组的数据构成。

2.DataFrame - 主要用于处理二维数据。

from pandas import Series, DataFrame

 -Series

eg
import pandas as pd
s1 = pd.Series([1,2,3,4])
s1 
// 0 1
   1 2
   2 3
   3 4 
   dtype: int64

s1.index
//RangeIndex(start=0, stop=4, step=1)

s1.values
//array([1,2,3,4])


#利用index
s2 = pd.Series([100,78,65,90],index=["Chinese","English","History","Maths"])
s2
// Chinese 100
   English  78
   History  65
   Maths    90
   dtype: int64

s2[["English","History"]] 
// English 78
   History 65
   dtype: int64


d1 = {"name":"John","Gender":"Male","Age":20}
s3 = pd.Series(d1)
#s3就跟平常的Series一样

-DataFrame

dfPerson = {'name':["Tom","Jack","Kitty","Eric"],'age':[20,21,20,21]}
personSheet = pd.DataFrame(dfPerson)

#形成了清晰的表格

//    name  age
  0    Tom   20
  1   Jack   21
  2  Kitty   20
  3   Eric   21


personSheet.head() #获取前五个数据

personSheet.columns  

personSheet.values

personSheet.age 

import bumpy as np
numframe = np.random.randn(10,5)  #10行5列
numSheet = pd.DataFrame(numframe)

- 传入数据

personInfo = pd.read_csv('dir',header=None,names=["column1",...,"columnN"])
#header = None 表示不将数据的第一行作为列名，且names自定义列名

personInfo = pd.read_excel('dir',headeNone,names=["","",...,""])

personInfo.shape #获取excel文件的行和列

-排序

dataSort = pd.Series(range(5), index=['b','a','e','c','d'])
 
dataSort.sort_index() #升序排列

dataSort.sort_index(ascending=False)  #降序排列

-分组

personInfoed = personInfo.groupby(['age'])


personInfoed.count() #求数量

 

 

 

 

 

 

本文地址：https://blog.csdn.net/weixin_43766746/article/details/107347969