Omid - Challenge 246

data-challenges
advanced-exercises
🔰 Table Transformation!
Published

March 24, 2026

Illustration for Omid - Challenge 246

Challenge Description

🔰 Table Transformation!

Solutions

library(tidyverse)
library(readxl)

path = "files/200-299/246/CH-246 Table Transformation.xlsx"
input = read_excel(path, range = "B2:H6")
test = read_excel(path, range = "B10:E14")

result = input %>%
  select_if(~ any(str_detect(., "\\*")))

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

  • Logic:

    • Reads the workbook ranges needed for the challenge

    • Parses the text patterns directly instead of relying on manual cleanup

  • 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 = "200-299/246/CH-246 Table Transformation.xlsx"

input = pd.read_excel(path,  usecols="B:H", skiprows=1, nrows=5)
test = pd.read_excel(path, usecols="B:E", skiprows=9, nrows=5)

result = input.loc[:, input.astype(str).apply(lambda col: col.str.contains(r"\*").any())]

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 core logic is clear, but the correct transformation pattern is not obvious from the raw input.

  • The challenge combines multiple reshaping, grouping, or parsing steps.