Im trying to return false if a user inputs a str instead of a int

Question

def playerTurn(ballCount):
    playerchoice = int(input("How many balls do you want"))
if playerchoice == playerchoice.isalpha():
    print("has to be a number")
    return False
ballCount = ballCount - playerchoice
if playerchoice == 0:
    print("you cant choose 0")
    

#This is what I have tried but the input is a int already and I don't know what to do, I am new with coding.