F12.9 Project: an impact report

Read trial.csv and print the report, in this order and these exact forms: - sessions: <n> - students: <n> - total minutes: <n> - one line per student, student <n>: <minutes> min, <cm> cm, numbered in the order they first appear - energy: <kwh> kWh rounded to 2 decimal places - cost: £<n> rounded to 2 decimal places - carbon: <n> g CO2 rounded to the nearest whole number - personal data in this report: none

# the two lines every program starts with: the commands, then the robot
from bugbot import *
connect()

WATTS = 60
PENCE_PER_KWH = 28
GRAMS_PER_KWH = 190

The hint students can ask for: Read the file and drop the header line. Give each new name the next number and keep its running totals, so the report can talk about students without naming them. Turn the total minutes into energy, then into money and carbon with the rates given.

A solution

from bugbot import *
connect()
WATTS = 60
PENCE_PER_KWH = 28
GRAMS_PER_KWH = 190

rows = open("trial.csv").read().strip().split("\n")[1:]
numbers = {}
minutes = {}
distance = {}
total_minutes = 0
for row in rows:
    name, email, mins, cm = row.split(",")
    if name not in numbers:
        numbers[name] = len(numbers) + 1
        minutes[name] = 0
        distance[name] = 0
    minutes[name] = minutes[name] + int(mins)
    distance[name] = distance[name] + int(cm)
    total_minutes = total_minutes + int(mins)
print("sessions:", len(rows))
print("students:", len(numbers))
print("total minutes:", total_minutes)
for name, n in numbers.items():
    print(f"student {n}: {minutes[name]} min, {distance[name]} cm")
kwh = WATTS * total_minutes / 60 / 1000
print(f"energy: {kwh:.2f} kWh")
print(f"cost: £{kwh * PENCE_PER_KWH / 100:.2f}")
print(f"carbon: {round(kwh * GRAMS_PER_KWH)} g CO2")
print("personal data in this report: none")

Any program that meets the task's checks is marked correct in the simulator; this is one way, not the only way.