Omid - Challenge 227

data-challenges
advanced-exercises
🔰 For this challenge, calculate the minimum and maximum values for each column.
Published

March 24, 2026

Illustration for Omid - Challenge 227

Challenge Description

🔰 For this challenge, calculate the minimum and maximum values for each column.

Solutions

library(tidyverse)
library(readxl)

path = "files/CH-227 Data Normalization Min-Max.xlsx"
input = read_excel(path, range = "B2:G8")
test = read_excel(path, range = "J2:O8")

result = input %>%
  mutate(across(where(is.numeric), ~ (. - min(.)) / (max(.) - min(.))))

all.equal(result, test)
#> [1] TRUE

  • Logic:

    • Reads the workbook ranges needed for the challenge

    • Builds the intermediate columns that drive the final result

  • Strengths:

    • The R solution stays close to the workbook rule and keeps the transformation compact.

  • Areas for Improvement:

    • The code assumes the sheet structure and source ranges remain stable.

  • Gem:

    • The strongest part of the solution is choosing the right intermediate representation before shaping the final output.
import pandas as pd

path = "CH-227 Data Normalization Min-Max.xlsx"

input = pd.read_excel(path, usecols="B:G", skiprows=1, nrows=7)
test = pd.read_excel(path, usecols="J:O", skiprows=1, nrows=7).rename(columns=lambda col: col.split('.1')[0] if '.1' in col else col)

result = (input - input.min()) / (input.max() - input.min())

print(result.equals(test)) # True

  • Logic:

    • Reads the workbook ranges needed for the challenge

  • Strengths:

    • The Python version follows the same rule in a direct dataframe-oriented implementation.

  • Areas for Improvement:

    • The code assumes the workbook layout remains stable, so any sheet redesign would require small adjustments.

  • Gem:

    • The implementation stays close to the original workbook rule instead of adding unnecessary abstraction.

Difficulty Level

This task is moderate:

  • The business rule is readable, but the workbook still requires careful implementation to reach the expected layout.