Series

Posted 2020-11-22 qianslup

一、定义

Series是一种类似于一维数组的对象，它由一组数据（各种numpy数据类型）以及一组与之相关的数据标签（索引）组成。

也可以看成一个定长的有序字典。

 

 二、创建 

2.1 无索引创建

如果未指定索引，索引默认为0只n-1

import  pandas as pd
obj_1 = pd.Series([‘1‘, ‘2‘, ‘3‘])
obj_2 = pd.Series((‘1‘, ‘2‘, ‘3‘))
print(‘obj_1‘, obj_1)
print(‘obj_2‘, obj_2)

 

 

2.2 有索引创建

import  pandas as pd
obj_1 = pd.Series([‘1‘, ‘2‘, ‘3‘], index=[‘a‘, ‘b‘, ‘c‘])
obj_2 = pd.Series((‘1‘, ‘2‘, ‘3‘), index=[‘a‘, ‘b‘, ‘c‘])
dict_1 = {‘a‘:1, ‘b‘:‘2‘, ‘c‘:‘3‘}
obj_3 = pd.Series(dict_1)
print(‘obj_1‘, obj_1)
print(‘obj_2‘, obj_2)
print(‘obj_3‘, obj_3)

 

 

三、操作

3.1 取值操作

import pandas as pd
series_1 = pd.Series([1, 2, 3], index=[‘a‘, ‘b‘, ‘c‘])
result_1 = series_1[‘a‘]
result_2 = series_1[[‘b‘, ‘c‘]]
result_3 = ‘c‘ in series_1
result_4 = ‘d‘ in series_1
result_5 = series_1[series_1 > 2]  # 布尔类型

print(‘result_1‘, result_1)
print(‘result_2‘, result_2)
print(‘result_3‘, result_3)
print(‘result_4‘, result_4)
print(‘result_5‘, result_5)

 

 

3.2 算术操作

import pandas as pd
series_1 = pd.Series([1, 2, 3], index=[‘a‘, ‘b‘, ‘c‘])
series_2 = pd.Series([4, 5, 6], index=[‘b‘, ‘c‘, ‘d‘])
result_1 = series_1 + series_2
result_2 = series_1 - 2
result_3 = series_1 * 2

print(‘result_1‘, result_1)
print(‘result_2‘, result_2)
print(‘result_3‘, result_3)

 

 3.3 name属性

Series对象本身及其索引都有?个name属性，该属性跟pandas
其他的关键功能关系?常密切