library(tidyverse)
library(readxl)
path = "files/Challenge1425.xlsx"
input = read_excel(path, range = "B3:D23")
test = read_excel(path, range = "F3:H7")
input = input %>%
mutate(Date = str_replace(Date, "29-02", "27-02") %>% dmy())
seq = seq.Date(min(input$Date), max(input$Date), by = "1 day") %>%
data.frame(Date = .) %>%
left_join(input, by = "Date") %>%
fill(`Staff No.`, .direction = "down") %>%
mutate(week = isoweek(Date)) %>%
summarise(`Total Hours` = sum(`Worked Hours`, na.rm = TRUE),
`Week Dates` = paste(min(Date), max(Date), sep = " - "),
.by = c("Staff No.", "week")) %>%
select(1,4,3)Crispo - Excel Challenge 14 2025
excel-challenges
weekly-exercises
Easy Sunday Excel Challenge

Challenge Description
Easy Sunday Excel Challenge
⭐ ⭐Create Weekly Groups and Sum
Solutions
Logic:
Reads the workbook range needed for the challenge
Aggregates or ranks values at the correct grouping level
Builds the intermediate helper columns that drive the final answer
Uses direct text-pattern extraction instead of manual cleanup
Strengths:
- The R solution stays compact and mirrors the workbook logic closely.
Areas for Improvement:
- The code assumes the workbook layout and named ranges remain stable.
Gem:
- The best part of the solution is choosing a tidy intermediate shape before producing the final answer.
import pandas as pd
import numpy as np
path = "files/Challenge1425.xlsx"
input = pd.read_excel(path, usecols="B:D", skiprows=2, nrows=21)
test = pd.read_excel(path, usecols="F:H", skiprows=2, nrows=4)
input['Date'] = input['Date'].str.replace("29-02", "27-02", regex=False)
input['Date'] = pd.to_datetime(input['Date'], format='%d-%m-%Y')
date_range = pd.date_range(start=input['Date'].min(), end=input['Date'].max(), freq='D')
seq = pd.DataFrame({'Date': date_range})
seq = seq.merge(input, on='Date', how='left')
seq['Staff No.'] = seq['Staff No.'].ffill()
seq['week'] = seq['Date'].dt.isocalendar().week
summary = (
seq.groupby(['Staff No.', 'week'])
.agg(
**{
'Total Hours': ('Worked Hours', lambda x: x.sum(skipna=True)),
'Week Dates': ('Date', lambda x: f"{x.min().strftime('%Y-%m-%d')} - {x.max().strftime('%Y-%m-%d')}")
}
)
.reset_index()
)
summary = summary[['Staff No.', 'Week Dates', 'Total Hours']]Logic:
Reads the workbook range needed for the challenge
Aggregates or ranks values at the correct grouping level
Strengths:
- The Python version keeps the same rule in a direct pandas-oriented workflow.
Areas for Improvement:
- As with the R version, any workbook layout change would require small adjustments.
Gem:
- The implementation stays close to the stated challenge instead of adding unnecessary complexity.
Difficulty Level
This task is moderate:
It combines familiar Excel-style logic with at least one non-trivial reshape, grouping, or parsing step.
The answer depends on getting the output layout exactly right.