质数

1、输入指定范围的素数

def prime(n):
    res = []
    for n in range(2,n+1):
        for i in range(2,n):
            if n % i == 0:
                break
        else:
            res.append(n)
    return res

print(prime(100))

2、将一个正整数分解质因子

def prime(n):
    res = []
    while n > 1:
        for i in range(2,n+1):
            if n % i == 0:
                n = int(n/i)
                res.append(i)
                break
    return res

s = input("请输入一个正整数：")
if s.isdigit() and int(s) > 0:
    # *.join(sequence)用*号连接元素序列
    print(s, '=', '*'.join([str(x) for x in prime(int(s))]))