#0137

Wide Monthly Sales to Long

MediumPandas25 min20 XP

Problem

Given product, jan, feb columns, return product, month, sales rows. Month values should be jan and feb.

Why This Matters

Tidy long format makes plotting, grouping, and modeling easier.

Function Signature

def sales_wide_to_long(df):

Examples

Example 1

Inputproduct A with jan=10 feb=20

Outputtwo rows for A

Each month column becomes a row.

Constraints

Return the exact requested structure.
Handle normal edge cases cleanly.
Prefer readable code over clever shortcuts.

CodePython

import pandas as pd

def sales_wide_to_long(df):
    """
    Input example: product A with jan=10 feb=20
    Return: two rows for A
    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 sales_wide_to_long(df):
    """
    Input example: product A with jan=10 feb=20
    Return: two rows for A
    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

Core example

Inputproduct A with jan=10 feb=20

Expectedtwo rows for A

Each month column becomes a row.

Hidden Test Categories

multiple productszero salesindex reset