Pandas入门系列（六) -- reindex_cannot reindex a non-unique index with a method or

数据分析汇总学习

https://blog.csdn.net/weixin_39778570/article/details/81157884

import numpy as np
import pandas as pd 
from pandas import Series, DataFrame

# 创建一个Series对象
s1 = Series([1,2,3,4], index=['A','B','C','D'])
s1
Out[51]: 
A    1
B    2
C    3
D    4
dtype: int64

# Series的reindex操作
s1.reindex(index=['A','B','C','D','E'])
Out[53]: 
A    1.0
B    2.0
C    3.0
D    4.0
E    NaN
dtype: float64

# 缺失值填充
s1.reindex(index=['A','B','C','D','E'], fill_value=10)
Out[54]: 
A     1
B     2
C     3
D     4
E    10
dtype: int64

# 创建一个Series对象s2
s2 = Series(['A','B','C'], index=[1,5,10])

s2
Out[57]: 
1     A
5     B
10    C
dtype: object
# reindex
s2.reindex(index=range(15))
Out[58]: 
0     NaN
1       A
2     NaN
3     NaN
4     NaN
5       B
6     NaN
7     NaN
8     NaN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56