Convert minutes in to days, hours and minutes

convert.py

def convert(minutes):

    if isinstance(minutes, int):
        return str(minutes/24/60) + " day, " + \
               str(minutes/60 % 24) + " hours, " + \
               str(minutes % 60) + " minutes"
    else:
        return "0 days, 0 hours, 0 minutes"


if __name__ == "__main__":

    values = [180, 181, 31, 1450, 1440, 1800, 1840, -100, None, 0]
    for val in values:
        print(str(val) + " minutes is " + convert(val))