Pandas: Get topmost n records within each group of a DataFrame

Last update on May 01 2025 12:52:57 (UTC/GMT +8 hours)

61. Get Topmost n Records Within Each Group

Write a Pandas program to get topmost n records within each group of a DataFrame.

Sample Solution :

Python Code :

import pandas as pd
d = {'col1': [1, 2, 3, 4, 7, 11], 'col2': [4, 5, 6, 9, 5, 0], 'col3': [7, 5, 8, 12, 1,11]}
df = pd.DataFrame(data=d)
print("Original DataFrame")
print(df)
print("\ntopmost n records within each group of a DataFrame:")
df1 = df.nlargest(3, 'col1')
print(df1)
df2 = df.nlargest(3, 'col2')
print(df2)
df3 = df.nlargest(3, 'col3')
print(df3)

Sample Output:

Original DataFrame
   col1  col2  col3
0     1     4     7
1     2     5     5
2     3     6     8
3     4     9    12
4     7     5     1
5    11     0    11

topmost n records within each group of a DataFrame:
   col1  col2  col3
5    11     0    11
4     7     5     1
3     4     9    12
   col1  col2  col3
3     4     9    12
2     3     6     8
1     2     5     5
4     7     5     1
   col1  col2  col3
3     4     9    12
5    11     0    11
2     3     6     8

For more Practice: Solve these Related Problems:

Write a Pandas program to group a DataFrame by a given column and then select the top n rows from each group based on another column.
Write a Pandas program to use the groupby() and head() methods to extract the top n records for each group and then merge the results.
Write a Pandas program to compute the top n highest values within each group and then output a multi-index DataFrame.
Write a Pandas program to group by a categorical column, sort each group by a numeric column, and then select the first n records.

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Python-Pandas Code Editor:

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