python笔记：3.2.1.1pandas数据结构_Series
# -*- coding: utf-8 -*-
"""
Created on Wed May 22 14:12:15 2019
@author: User
"""
import pandas as pd
s1 = pd.Series([100, 78, 59, 63])
print('\n')
print(s1)
print('\n s1.values:')
print(s1.values)
print('\n s1.index:')
print(s1.index)
print('\n 赋值方法改写Series索引:')
s1.index=['No.1','No.2','No.3','No.4']
print(s1)
print('\n 指定index关键字:')
s2 = pd.Series([100, 78, 59, 63], index=['Math','English','Literature','History'])
print(s2)
print('\n 通过索引访问数据元素:')
print(s2[['English','Literature']])
print('\n Series由字典转换而来:')
d3={'Name':'zhang san','Gender':'Male','Age':'19','Weight':'76'}
s3=pd.Series(d3)
print(s3)
print('\n Series索引由数组内容代替:')
student_attr=['ID','Name','Gender','Age','Grade','Height','Weight']
s4=pd.Series(d3,index=student_attr)
print(s4)
print('\n 检测缺失值:')
print(pd.isnull(s4))
print('\n Series的一个重要功能是自动对齐索引数据:')
print(s3+s4)
print('\n Series对象本身及索引都具有name属性:')
s4.name='Student\'s profile'
s4.index.name='Attribute'
print(s4)
print('\n reindex重新索引:')
print(s4.reindex(index=['Name','ID','Age','Gender','Height','Weight','Grade']))
print('\n 新增索引:')
s4.index=['b','g','a','c','e','f','d']
print(s4)
print('\n reindex:')
print(s4.reindex(index=['a','b','c','d','e','f','g','h']))
print('\n reindex并不会改变原索引的实际存储位置，而是返回一个重新索引的视图:')
print(s4)
print('\n 使用 reindex(index,method=\'***\')的时候，原index必须是单调的:')
s4.index=[0,2,3,6,8,9,11]
print(s4.reindex(range(10),method='ffill'))运行：
0 100
1 78
2 59
3 63
dtype: int64
s1.values:
[100 78 59 63]
s1.index:
RangeIndex(start=0, stop=4, step=1)
赋值方法改写Series索引:
No.1 100
No.2 78
No.3 59
No.4 63
dtype: int64
指定index关键字:
Math 100
English 78
Literature 59
History 63
dtype: int64
通过索引访问数据元素:
English 78
Literature 59
dtype: int64
Series由字典转换而来:
Name zhang san
Gender Male
Age 19
Weight 76
dtype: object
Series索引由数组内容代替:
ID NaN
Name zhang san
Gender Male
Age 19
Grade NaN
Height NaN
Weight 76
dtype: object
检测缺失值:
ID True
Name False
Gender False
Age False
Grade True
Height True
Weight False
dtype: bool
Series的一个重要功能是自动对齐索引数据:
Age 1919
Gender MaleMale
Grade NaN
Height NaN
ID NaN
Name zhang sanzhang san
Weight 7676
dtype: object
Series对象本身及索引都具有name属性:
Attribute
ID NaN
Name zhang san
Gender Male
Age 19
Grade NaN
Height NaN
Weight 76
Name: Student's profile, dtype: object
reindex重新索引:
Attribute
Name zhang san
ID NaN
Age 19
Gender Male
Height NaN
Weight 76
Grade NaN
Name: Student's profile, dtype: object
新增索引:
b NaN
g zhang san
a Male
c 19
e NaN
f NaN
d 76
Name: Student's profile, dtype: object
reindex:
a Male
b NaN
c 19
d 76
e NaN
f NaN
g zhang san
h NaN
Name: Student's profile, dtype: object
reindex并不会改变原索引的实际存储位置，而是返回一个重新索引的视图:
b NaN
g zhang san
a Male
c 19
e NaN
f NaN
d 76
Name: Student's profile, dtype: object
使用 reindex(index,method='***')的时候，原index必须是单调的:
0 NaN
1 NaN
2 zhang san
3 Male
4 Male
5 Male
6 19
7 19
8 NaN
9 NaN
Name: Student's profile, dtype: object