Omid - Challenge 341

data-challenges
advanced-exercises
🔰 Challenge 341: Filter!
Published

March 24, 2026

Illustration for Omid - Challenge 341

Challenge Description

🔰 Challenge 341: Filter!

Solutions

library(tidyverse)
library(readxl)

path <- "300-399/341/CH-341 Filter.xlsx"
input <- read_excel(path, range = "B3:B10")
test <- read_excel(path, range = "F3:F6")

result = input %>%
  filter(str_detect(ID, "N.*M"))

all.equal(result$ID, test$ID)
# [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 = "300-399\\341\\CH-341 Filter.xlsx"
input = pd.read_excel(path, usecols="B", nrows = 8, skiprows = 2)
test = pd.read_excel(path, usecols="F", nrows=3, skiprows=2).rename(columns=lambda c: c.replace('.1', ''))

filtered = input[input["ID"].str.contains(r"N.*M", na=False)].reset_index(drop=True)

print(filtered.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.