51    return aqi
52
53#Function to prompt user for input and calculate PM2.5 and PM10 concentrations and AQI.
54def calc_pm():55    while True:
56        print("\nPlease select the particle type you want to count.:")
57        print("[1] PM2.5")

28#Calculate AQI based on pollutant concentration.
29#concentration: float, concentration value in µg/m³
30#pollutant: string, one of 'PM2.5' or 'PM10'
31def calculate_aqi(concentration, pollutant):32    if pollutant == 'PM2.5':
33        c_low = [0, 12.1, 35.5, 55.5, 150.5, 250.5, 350.5, 500.5]
34        c_high = [12, 35.4, 55.4, 150.4, 250.4, 350.4, 500.4, 999.9]