python eval

输入数值  eval(input('输入数值：'))

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n=int(input("请输入购买的个数："))

if n==1:

    prize=150

    print(prize)

elif 2<=n<=3:

    prize=150*0.9*n

print(prize)

    elif 4<=n<=9:

    prize=150*0.8*n

    print(prize)

elif n>=10:

    prize=150*0.7*n

    print(prize)