Crispo - Excel Challenge 17 2025

excel-challenges
weekly-exercises
Easy Sunday Excel Challenge
Published

April 21, 2025

Illustration for Crispo - Excel Challenge 17 2025

Challenge Description

Easy Sunday Excel Challenge

⭐ Easy Sunday Excel Challenge

Solutions

  • Logic:

    • Applies the workbook rule directly and shapes the expected output

  • Strengths:

    • The R solution stays compact and mirrors the workbook logic closely.

  • Areas for Improvement:

    • The code assumes the workbook layout and named ranges remain stable.

  • Gem:

    • The best part of the solution is choosing a tidy intermediate shape before producing the final answer.
import pandas as pd

path = "files/Challenge15-2025.xlsx"
input = pd.read_excel(path, usecols="B:G", skiprows=2, nrows=2)
test = pd.read_excel(path, usecols="I:K", skiprows=2, nrows=10)

input = input.fillna(0)
result = (
    input.rename(columns={input.columns[0]: "product"})
    .melt(id_vars="product", var_name="month", value_name="sales")
    .ffill()
)

month_order = ["Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
result["month"] = pd.Categorical(result["month"], categories=month_order, ordered=True)
result = (
    result.dropna()
    .sort_values(["product", "month"])
    .reset_index(drop=True)
    .assign(diff=lambda df: df.groupby("product")["sales"].diff())
    .query("diff > 0")
    .loc[lambda df: df.index.repeat(df["diff"].astype(int))]
    .assign(Req=1)
    .drop(columns=["sales", "diff"])
    .reset_index(drop=True)
)
result["month"] = result["month"].astype(str)
result.columns = test.columns

print(result.equals(test)) # True

  • Logic:

    • Reads the workbook range needed for the challenge

    • Reshapes the data to the grain required by the task

    • Aggregates or ranks values at the correct grouping level

    • Builds the intermediate helper columns that drive the final answer

  • Strengths:

    • The Python version keeps the same rule in a direct pandas-oriented workflow.

  • Areas for Improvement:

    • As with the R version, any workbook layout change would require small adjustments.

  • Gem:

    • The implementation stays close to the stated challenge instead of adding unnecessary complexity.

Difficulty Level

This task is easy to moderate:

  • The business rule is readable, but the workbook still needs a few careful transformation steps.