An automated greenhouse control program is being developed to display soil moisture records and calculate water usage costs. It displays each moisture level stored in an array of readings.

• It sums up additional water allocations (in litres) entered by the user, until the user enters -1.0.
• It then calculates a tax rate. When the total water allocated is over 150.0 litres, the tax rate is 18%. Otherwise, the tax rate is 8%.

Program Code

1: TAX_THRESHOLD = 150.0
2: moisture_readings = [45.2, 48.0, 39.5, 55.1, 42.8]
3: total_water = 0.0
4: print("Historical Moisture Levels:")
5: for level in moisture_readings:
6:     print(str(level) + "%")
7: allocation = float(input("Enter water volume in litres (-1 to stop): "))
8: while allocation != -1.0:
9:     total_water = total_water + allocation
10:    allocation = float(input("Enter water volume in litres (-1 to stop): "))
11: if total_water > TAX_THRESHOLD:
12:    tax_rate = 0.18
13: else:
14:    tax_rate = 0.08
15: final_cost = total_water * (1 + tax_rate)
16: print("Total cost of water: £" + str(final_cost))

Task

Identify the code features requested below from the program snippet shown above: