2891. Method Chaining

DataFrame animals

Column Name	Type
name	object
species	object
age	int
weight	int

Instructions

• Write a solution to list the names of animals that weigh strictly more than 100 kilograms.
• Return the animals sorted by weight in descending order.
• The result format is in the following example.

Example

Input:

name	species	age	weight
Tatiana	Snake	98	464
Khaled	Giraffe	50	41
Alex	Leopard	6	328
Jonathan	Monkey	45	463
Stefan	Bear	100	50
Tommy	Panda	26	349

Output:

name
Tatiana
Jonathan
Tommy
Alex

Explanation:

All animals weighing more than $100$ should be included in the results table.

Tatiana's weight is $464$, Jonathan's weight is $463$, Tommy's weight is $349$, and Alex's weight is $328$.

The results should be sorted in descending order of weight.

Submissions

import pandas as pd

def findHeavyAnimals(animals: pd.DataFrame) -> pd.DataFrame:
    heavy_animals = animals[animals['weight'] > 100]
    sorted_animals = heavy_animals.sort_values(by='weight', ascending=False)
    return sorted_animals[['name']]

Explanation

Python (Pandas)

Submitted by @noeyislearning

• import pandas as pd: This line imports the pandas library, which is a powerful tool for data manipulation and analysis in Python, and aliases it as pd.
• def findHeavyAnimals(animals: pd.DataFrame) -> pd.DataFrame:: The function findHeavyAnimals takes one parameter, animals, which is expected to be a pandas DataFrame. The type hint pd.DataFrame is used for both the parameter and the return type, indicating that the function accepts a DataFrame as input and returns a DataFrame.
• heavy_animals = animals[animals['weight'] > 100]: This line filters the input DataFrame animals to include only the rows where the value in the 'weight' column is greater than 100. The result is stored in the heavy_animals DataFrame.
• sorted_animals = heavy_animals.sort_values(by='weight', ascending=False): The sort_values method is used to sort the heavy_animals DataFrame by the 'weight' column in descending order. The ascending=False argument specifies that the sorting should be done in descending order.
• return sorted_animals[['name']]: The function returns a DataFrame containing only the 'name' column of the sorted_animals DataFrame. This DataFrame contains the names of animals that weigh more than 100 kilograms, sorted by weight in descending order.