Python | Pandas DataFrame.nsmallest()

Python is a great language for doing data analysis, primarily because of the fantastic ecosystem of data-centric python packages. Pandas is one of those packages and makes importing and analyzing data much easier.
Pandas nsmallest() method is used to get n least values from a data frame or a series.
 

Syntax: DataFrame.nsmallest(n, columns, keep='first')
Parameters: 
n: int, Number of values to select 
columns: Column to check for least values or user can select column while calling too. [For example: data["age"].nsmallest(3) OR data.nsmallest(3, "age")] 
keep: object to set which value to select if duplicates exit. Options are 'first' or 'last'. 
 

To download the CSV file used, Click Here.
Example #1: Extracting Least 5 values 
In this example least 5 values are extracted and then compared to the other sorted by the sort_values() function. 
NaN values are removed before trying this method.
Refer sort_values and dropna().
 

# importing pandas package
import pandas as pd

# making data frame from csv file 
data = pd.read_csv("employees.csv")

# removing null values
data.dropna(inplace = True)

# extracting least 5
least5 = data.nsmallest(5, "Salary")

# display
least5

Output: 
 

  
Example #2: Sorting by sort_values()
 

# importing pandas package
import pandas as pd

# making data frame from csv file 
data = pd.read_csv("employees.csv")

# removing null values
data.dropna(inplace = True)

# sorting in ascending order
data.sort_values("Salary", ascending = True, inplace = True)

# displaying top 5 values
data.head()

Output:
As shown in the output image, the values returned by both functions are similar.