价格等于单价乘于数量

如果商品数量大于100，会享受10%的折扣；50-100之间会享受5%的折扣；小于50没有折扣

def getAmount(num,price):
    amount=num*price
    if num>100:
        amount=amount*0.9
    elif num>50:
        amount=amount*0.95
    else:
        amount=amount
    return amount
print(getAmount(60,20))