Python素数

import math

def is_prime(num):
    if num < 2:
        return False
    for i in range(2, int(math.sqrt(num)) + 1):
        if num % i == 0:
            return False
    return True

# 示例
print(is_prime(7))  # 输出 True
print(is_prime(10))  # 输出 False

def primes_sieve(limit):
    limitn = limit + 1
    primes = [True] * limitn
    primes[0] = primes[1] = False
    for (i, is_prime) in enumerate(primes):
        if is_prime:
            for n in range(i*i, limitn, i):
                primes[n] = False
    return primes

def is_prime(num):
    if num < 2:
        return False
    primes = primes_sieve(int(math.sqrt(num)) + 1)
    return primes[num]

# 示例
print(is_prime(7))  # 输出 True
print(is_prime(10))  # 输出 False