Retrieving the smallest and largest n numbers from a Pandas Series

Overview:

Largest 'n' numbers and smallest 'n' numbers from a Pandas series can be obtained through the methods nlargest() and nsmallest().
Both the methods, nsmallest() and nlargest() return a pandas series.
The original index from the main series is retained in the new series returned by nsmallest() and nlargest() methods.

Example – Getting ‘n’ smallest numbers from a Pandas Series:

# Example Python program to get the n smallest numbers from a Pandas series

import pandas as pds

# List of numbers

listOfNums = [5, 1, 10, 15, 75, 40, 35, 65, 70];

# Create a pandas Series

series = pds.Series(listOfNums);

# Get a series with three smallest numbers from the main series

nSmallSeries3 = series.nsmallest(3);

# Get a series with five smallest numbers from the main series

nSmallSeries5 = series.nsmallest(5);

print("Series obtained with 3 smallest numbers:");

print(nSmallSeries3);

print("Series obtained with 5 smallest numbers:");

print(nSmallSeries5);

Output:

Series obtained with 3 smallest numbers:

1 1

0 5

2 10

dtype: int64

Series obtained with 5 smallest numbers:

1 1

0 5

2 10

3 15

6 35

dtype: int64

Example – Getting ‘n’ largest numbers from a Pandas Series:

# Example Python program to get the n largest numbers from a Pandas series

import pandas as pds

tupleOfNumbers = (0.1, 0.4, 0.2, 0.7, 0.6, 0.8, 1.2, 0.75, 0.05, 0.15);

series = pds.Series(tupleOfNumbers);

series4Large = series.nlargest(4);

series6Large = series.nlargest(6);

print("Series with four largest elements from the original series:");

print(series4Large);

print("Series with six largest elements from the original series:");

series6Large = series.nlargest(6);

print(series6Large);

Output:

Series with four largest elements from the original series:

6 1.20

5 0.80

7 0.75

3 0.70

dtype: float64

Series with six largest elements from the original series:

6 1.20

5 0.80

7 0.75

3 0.70

4 0.60

1 0.40

dtype: float64