How to keep looping until the user input is valid ?

[KyawMyo]

def get_valid_input(value):
    while True:
        try:
            return float(input(value))
        except ValueError:
            print('Oops, that was not a valid number. Try again...')

def calculate_set_of_cable(amp, cableSize):
    cableSize = int(cableSize)
    if cableSize not in (25, 35, 50, 70, 95, 120, 150, 195, 250, 300, 500):
        cableSize = input('Please enter a valid cable size')  # Please advise if user input wrongly, want to keep looping util the correct value.
    else:
        if cableSize == 25:
            return amp / 53
        elif cableSize == 35:
            return amp / 71
        # the code not finished yet



if __name__ == '__main__':
    while True:
        amp = get_valid_input('Please enter an Ampere:')
        cableSize = get_valid_input('Please enter the cable size:')
        set_of_cable = calculate_set_of_cable(amp, cableSize)
        print(f'The cables for {amp} are {set_of_cable:.2f} sets per phase')
        print ('The program end here, Good Luck!!\n----------------------')