#0082

Melt Wide Score Columns

MediumPandas18 min20 XP

Problem

Given a DataFrame with user_id, math_score, and sql_score, return a long DataFrame with columns user_id, subject, score. subject should be math or sql.

Why This Matters

Many datasets arrive wide, but plotting and grouped analysis often work better in long format.

Function Signature

def melt_scores(df):

Examples

Example 1

Inputone row with math_score and sql_score

Outputtwo rows

Each score column becomes a subject row.

Constraints

Return columns user_id, subject, score.
Remove _score from subject names.
Reset the index.

CodePython

import pandas as pd

def melt_scores(df):
    """
    Input example: one row with math_score and sql_score
    Return: two rows
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return df

import pandas as pd

def melt_scores(df):
    """
    Input example: one row with math_score and sql_score
    Return: two rows
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return df

Visible browser tests run here when available.

Testcases1 visible / 3 hidden categories

Two users two subjects

Inputwide scores

Expectedfour long rows

Each user has one row per subject.

Hidden Test Categories

single userindex resetsubject name cleanup