Omid - Challenge 371

data-challenges
advanced-exercises
🔰 In the id column in the question table, extract all the parts befor and after two repetitive characters.
Published

March 24, 2026

Illustration for Omid - Challenge 371

Challenge Description

🔰 In the id column in the question table, extract all the parts befor and after two repetitive characters.

Solutions

library(tidyverse)
library(readxl)

path <- "300-399/371/CH-371 Text Cleaning.xlsx"
input <- read_excel(path, range = "B3:B8")
test <- read_excel(path, range = "E3:E8")


result = input %>%
  mutate(cleaned = str_remove_all(ID, "(.).*?\\1")) %>%
  select(ID = cleaned)

all.equal(result$ID, test$ID)
# [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 = "300-399/371/CH-371 Text Cleaning.xlsx"

input = pd.read_excel(path, usecols="B", skiprows=2, nrows=6)
test = pd.read_excel(path, usecols="E", skiprows=2, nrows=6)

def remove_wrapped(s):
    pattern = re.compile(r'(.)[^\\1]*?\1')
    while pattern.search(s):
        s = pattern.sub('', s)
    return s

result = input['ID'].apply(remove_wrapped)
print(result.equals(test['ID.1']))
# Output: True

  • Logic:

    • Reads the workbook ranges needed for the challenge

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

    • Applies the rule iteratively until the output stabilizes

  • 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.