python 求素数

prime number : 又称素数或质数，该数除了1和它本身以外，不能被任何数整除，2为最小质数。

# 输出 2 到 99 之间的质数：
for n in range(2, 100):
    for x in range(2, n):
        if n % x == 0:
            break;
    else:
        print(f"{n} is a prime number")

else 关键字，可用于 for 或 while 循环，当 循环执行没有遇到 break，或其他错误，则 else 里的语句执行，这种写法能使code变得简洁。

2 is a prime number
3 is a prime number
5 is a prime number
7 is a prime number
11 is a prime number
13 is a prime number
17 is a prime number
19 is a prime number
23 is a prime number
29 is a prime number
31 is a prime number
37 is a prime number
41 is a prime number
43 is a prime number
47 is a prime number
53 is a prime number
59 is a prime number
61 is a prime number
67 is a prime number
71 is a prime number
73 is a prime number
79 is a prime number
83 is a prime number
89 is a prime number
97 is a prime number