Omid - Challenge 95

data-challenges
advanced-exercises
🔰 In the Question table, monthly inventory levels of products are provided.
Published

March 24, 2026

Illustration for Omid - Challenge 95

Challenge Description

🔰 In the Question table, monthly inventory levels of products are provided.

Solutions

library(tidyverse)
library(readxl)

path = "files/CH-095 Last Inventory.xlsx"
input = read_excel(path, range = "B2:G7")
test  = read_excel(path, range = "I2:J7")


result = input %>%
  rowwise() %>%
  mutate(`Last Inventory` = last(na.omit(c_across(-Product)))) %>%
  ungroup() %>%
  select(c(1,7))

identical(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

path = "CH-095 Last Inventory.xlsx"
input = pd.read_excel(path, usecols = "B:G", skiprows = 1)
test  = pd.read_excel(path, usecols = "i:j", skiprows = 1)
test.columns = test.columns.str.replace(".1", "")

result = input.copy()
result['Last Inventory'] = input.iloc[:, 1:]\
    .apply(lambda x: x[x.last_valid_index()], axis = 1)\
    .astype("int64")
result = result[['Product', 'Last Inventory']]

print(result.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.