Omid - Challenge 146

data-challenges
advanced-exercises
🔰 Challenge 146: Column Splitting!
Published

March 24, 2026

Illustration for Omid - Challenge 146

Challenge Description

🔰 Challenge 146: Column Splitting!

Solutions

library(tidyverse)
library(readxl)

path = "files/CH-146 Column Splitting.xlsx"
input = read_excel(path, range = "B2:B8")
test  = read_excel(path, range = "D2:F8")

result = input %>%
  separate(ID, into = c("ID.1", "ID.2", "ID.3"), sep = "\\|", fill = "right") %>%
  mutate(ID.1 = ifelse(is.na(ID.1), NA, ID.1),
         ID.2 = ifelse(is.na(ID.2), NA, paste(ID.1, ID.2, sep = "")),
         ID.3 = ifelse(is.na(ID.3), NA, paste(ID.2, ID.3, sep = "")))

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

  • Logic:

    • Reads the workbook ranges needed for the challenge

    • Builds the intermediate columns that drive the final result

  • 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 numpy as np

path = "CH-146 Column Splitting.xlsx"
input = pd.read_excel(path, usecols="B", skiprows=1, nrows=7)
test = pd.read_excel(path, usecols="D:F", skiprows=1, nrows=7)

input[['ID.1', 'ID.2', 'ID.3']] = input['ID'].str.split('|', expand=True)

input[['ID.1', 'ID.2', 'ID.3']] = input[['ID.1', 'ID.2', 'ID.3']].apply(lambda col: col.fillna(pd.NA))
input['ID.2'] = input.apply(lambda row: np.NaN if pd.isna(row['ID.2']) else f"{row['ID.1']}{row['ID.2']}", axis=1)
input['ID.3'] = input.apply(lambda row: np.NaN if pd.isna(row['ID.3']) else f"{row['ID.2']}{row['ID.3']}", axis=1)
input = input.drop(columns=['ID'])

print(input.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 business rule is readable, but the workbook still requires careful implementation to reach the expected layout.