Sample Windchill

# windchill

def windchill(t, v):
    """
    windchill(t,v) takes a temperature and wind speed and returns the
    windchill factor.

    t = temperature in Farhenheit
    v = wind speed in miles per hour

    >>> windchill(5,10)
    -9.737344294197483
    >>> windchill(20,20)
    4.242781599820461
    >>> windchill(-10,50)
    -45.32064601872968
    """
    return 35.74 + 0.6215 * t - 35.75 * v**0.16 + 0.4275 * t * v**0.16

def getuservalue(s):
    while True:
        try:
            val = int(input(s))
            return val
        except ValueError:
            print("Error! - Please enter an integer.")


def main():
    tmin = getuservalue('Starting temperature in degrees Fahrenheit: ')
    tmax = getuservalue('Ending temperature: ')
    tinc = getuservalue('Increment value for temperature: ')

    vmin = getuservalue('\nStarting wind speed in miles per hour: ')
    vmax = getuservalue('Ending wind speed: ')
    vinc = getuservalue('Increment value for wind speed: ')

    print('\n\n')

    # output column header
    print("T(degF)", end="")
    for v in range(vmin, vmax+vinc,vinc):
        print("{:4d} mph".format(v),end="")

    print("\n=======\t",end="")
    for v in range(vmin, vmax+vinc,vinc):
        print("=======\t",end="")

    # print the table
    print()
    for t in range(tmin, tmax+tinc, tinc):
        print("{:-6d}".format(t),end="|")
        for v in range(vmin, vmax+vinc, vinc):
            print("\t{:-7.2f}".format(windchill(t,v)),end="")
        print()

    temp = input('[press ENTER to quit]')


if __name__ == "__main__":
    import doctest
    doctest.testmod()
    main()