自建进程池

# 示例19-12 sequential.py：对一个小型数据集做指数检测(顺序执行版)
"""
sequential.py: CPU密集型工作的舒徐执行版，多线程版和多进程版的比较基准
"""
from time import perf_counter
from typing import NamedTuple

from primes import is_prime, NUMBERS


class Result(NamedTuple): # 1
    prime: bool
    elapsed: float


def check(n: int) -> Result: # 2
    t0 = perf_counter()
    prime = is_prime(n)
    return Result(prime, perf_counter() - t0)


def main() -> None:
    print(f'Checking {len(NUMBERS)} numbers sequentially:')
    t0 = perf_counter()
    for n in NUMBERS: # 3
        prime, elapsed = check(n)
        label = 'P' if prime else ' '
        print(f'{n:16} {label} {elapsed:9.6f}s')

    elapsed =  perf_counter()  - t0 # 4
    print(f'Total time:{elapsed:.2f}s')
    

if __name__ == '__main__':
    main()

1. check函数 返回一个Result 元组，包含is_prime 调用返回的布尔值和用时
2. check(n) 调用 is_prime(n)，并计算用时，返回一个Result
3. 调用check检查样本中的每个数，显示结果。
4. 计算并显示总用时。