在 pandas dataframe 中设置和重置索引不起作用

Question

import numpy as np
import pandas as pd
np.random.seed(121) 
randArr =np.random.randint(0,100,20).reshape(5,4) 
df =pd.DataFrame(randArr,np.arange(101,106,1),['PDS','Algo','SE','INS']) 
df.index.name='RollNo'
print(df)
print("")
df.reset_index()
print(df)
print("")
df.set_index('PDS')
print(df)
print("")

Output:(not coming as expected)

        PDS  Algo  SE  INS
RollNo                    
101      66    85   8   95
102      65    52  83   96
103      46    34  52   60
104      54     3  94   52
105      57    75  88   39

        PDS  Algo  SE  INS
RollNo                    
101      66    85   8   95
102      65    52  83   96
103      46    34  52   60
104      54     3  94   52
105      57    75  88   39

        PDS  Algo  SE  INS
RollNo                    
101      66    85   8   95
102      65    52  83   96
103      46    34  52   60
104      54     3  94   52
105      57    75  88   39

Answer 1

You need assign the result back

df = df.reset_index()

df = df.set_index('PDS')

Or you can use inplace argument

df.reset_index(inplace=True)

df.set_index('PDS', inplace=True)