重新索引Series时，值将变为NaN

Question

import numpy as np
from pandas import DataFrame,Series
n = np.arange(0,5)
s = Series(n,index =['a','b','c','d','e'])
print(s)
s= s.reindex(['A','B','C','D','E'])
print(s)

Output:

a    0
b    1
c    2
d    3
e    4
dtype: int64
A   NaN
B   NaN
C   NaN
D   NaN
E   NaN
dtype: float64

Answer 1

Use the script below. It will change the value of the index to your desired values. Reindex will not change the values but will change the order of the records and if such index value is not found, it will put NaN.

OLD:

s= s.reindex(['A','B','C','D','E'])

New:

s.index=['A','B','C','D','E']

Result:

A    0
B    1
C    2
D    3
E    4
dtype: int64