python练习题

1 判断一个数字是否是质数.

for x in range(100):
    for y in range(2, x):
        if x%y == 0:
            break
    else:
        print(x)

2 写代码实现 1-3+5-7+9-11+.....-99=?

i = 1
s = 0
while i<=100:
    if i%4 == 1:
        s = s + i
    else:
        s = s - i
    i = i + 2
print(s)

3 计算∏, 计算公司为∏/4 = 1-1/3+1/5-1/7+1/9+........., 直到最后一项的绝对值小于10的负六次方为止.

n = 0
p = 1
while p<1000000:
    if p%4 == 1:
        n = n + 1/p
    else:
        n = n -1/p
    p = p + 2
print(n*4)

4 制作简易版的计算器

a = input('请输入第一个数字:')
a = int(a)
b = input('请输入运算符:')
c = input('请输入第二个数字:')
c = int(c)
if b == '+':
    print(a,b,c,'=',a+c)
elif b == '-':
    print(a,b,c,'=',a-c)
elif b == '*':
    print(a,b,c,'=',a*c)
else:
    print(a,b,c,'=',a/c)

5 判断一个数字是奇数还是偶数

a = int(input('请输入一个数字:'))
if a%2 == 0:
    print(a, '是偶数')
else:
    print(a, '是奇数')

6 一位四位数乘以9等于它的逆序, 即abcd*9 = dcba

abcd = 1000
while abcd<10000:
    a = abcd//1000
    bcd = abcd%1000
    b = bcd//100
    cd = bcd%100
    c = cd//10
    d = cd%10
    if d*1000+c*100+b*10+a == abcd:
        print(abcd)
    abcd = abcd+1

7 用while循环计算100项的平方数列和, 即1+4+9+....+100000

a = 1
s = 0
while a<=100:
    s = s+a*a
    a = a + 1
print(s)