Omid - Challenge 221

data-challenges
advanced-exercises
🔰 Extract the upper case characters
Published

March 24, 2026

Illustration for Omid - Challenge 221

Challenge Description

🔰 Extract the upper case characters

Solutions

library(tidyverse)
library(readxl)

path = "files/CH-221 Combining the columns.xlsx"
input = read_excel(path, range = "B2:B7")
test = read_excel(path, range = "E2:E7")

result = input %>%
  mutate(Text = str_remove_all(Text, "[a-z]"))

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

  • Logic:

    • Reads the workbook ranges needed for the challenge

    • Builds the intermediate columns that drive the final result

    • 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
import re

path = "CH-221 Combining the columns.xlsx"
input_data = pd.read_excel(path, usecols="B", skiprows=1, nrows=6)
test = pd.read_excel(path, usecols="E", skiprows=1, nrows=6).rename(columns=lambda col: col.replace('.1', ''))

input_data['Text'] = input_data['Text'].str.replace(r'[a-z]', '', regex=True)

print(input_data.equals(test)) # True

  • Logic:

    • Reads the workbook ranges needed for the challenge

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

  • 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.