Omid - Challenge 39

data-challenges
advanced-exercises
🔰 : Transformation!
Published

March 24, 2026

Illustration for Omid - Challenge 39

Challenge Description

🔰 : Transformation!

Solutions

library(tidyverse)
library(readxl)

input = read_excel("files/CH-039 Transformation.xlsx", range = 'B2:E10', col_names = F)
test  = read_excel("files/CH-039 Transformation.xlsx", range = 'G1:G22')


result = input %>%
  pivot_longer(everything(), names_to = NULL) %>%
  arrange(value) %>%
  na.omit() %>%
  distinct()

identical(result$value, test$`Result - Unique Code`)
# [1] TRUE

  • Logic:

    • Reads the workbook ranges needed for the challenge

    • Reshapes the data into the grain required by the task

  • 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

input = pd.read_excel("CH-039 Transformation.xlsx", sheet_name="Sheet1", usecols="B:E", nrows=9)
test  = pd.read_excel("CH-039 Transformation.xlsx", sheet_name="Sheet1", usecols="G",  nrows=22)

input = input.stack().reset_index(drop=True)
input = input.sort_values().drop_duplicates().reset_index(drop=True)
input = pd.DataFrame(input, columns=['result'])

print(input['result'].equals(test['Result - Unique Code'])) # 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.