Omid - Challenge 359

data-challenges
advanced-exercises
🔰 Result Question Total Sales Product ID Date Customer ID XNM-13 XNM-07
Published

March 24, 2026

Illustration for Omid - Challenge 359

Challenge Description

🔰 Result Question Total Sales Product ID Date Customer ID XNM-13 XNM-07

Solutions

library(tidyverse)
library(readxl)

path <- "300-399/359/CH-359 Replacement.xlsx"
input <- read_excel(path, range = "B3:E10")
test <- read_excel(path, range = "G3:J10")

result = input %>%
  add_count(`Customer ID`) %>%
  mutate(`Customer ID` = ifelse(n == 1, "Other", `Customer ID`)) %>%
  select(-n)

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

path = "300-399/359/CH-359 Replacement.xlsx"
input = pd.read_excel(path, usecols="B:E", skiprows=2, nrows=8)
test = pd.read_excel(path, usecols="G:J", skiprows=2, nrows=8).rename(columns=lambda col: col.replace(".1", ""))

input["Customer ID"] = input["Customer ID"].where(input["Customer ID"].map(input["Customer ID"].value_counts()) != 1, "Other")

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.