CODEWITHSUNDEEP
pythonpandasdataframeindexing
gabboshow
gabboshow

Reputation: 5559

renaming pandas dataframe indeces using index and column values

I have a dataframe df

df
 Name 
0   A
1   A
2   B
3   B
4   C
5   D
6   E
7   F
8   G
9   H

How can I rename the ideces of the dataframe so that 

df
 Name 
0_A   A
1_A   A
2_B   B
3_B   B
4_C   C
5_D   D
6_E   E
7_F   F
8_G   G
9_H   H

Upvotes: 1

Views: 61

Answers (1)

jezrael
jezrael

Reputation: 862481

1.

Assign to index concatenated string, first cast it to str 

df.index = df.index.astype(str) + '_' + df['Name']
#for remove index name
df.index.name = None
print (df)
    Name
0_A    A
1_A    A
2_B    B
3_B    B
4_C    C
5_D    D
6_E    E
7_F    F
8_G    G
9_H    H

2.

similar solution with set_index and rename_axis:

df = df.set_index(df.index.astype(str) + '_' + df['Name']).rename_axis(None)
print (df)
    Name
0_A    A
1_A    A
2_B    B
3_B    B
4_C    C
5_D    D
6_E    E
7_F    F
8_G    G
9_H    H

3.

Solution with str.cat:

df = df.set_index(df.index.astype(str).str.cat(df['Name'], sep='_'))
print (df)
    Name
0_A    A
1_A    A
2_B    B
3_B    B
4_C    C
5_D    D
6_E    E
7_F    F
8_G    G
9_H    H

4.

list comprehension solution:

df.index = ['{0[0]}_{0[1]}'.format(x) for x in zip(df.index, df['Name'])]
print (df)
    Name
0_A    A
1_A    A
2_B    B
3_B    B
4_C    C
5_D    D
6_E    E
7_F    F
8_G    G
9_H    H

Upvotes: 1

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