手写myscrapy（八）

项目地址：https://gitee.com/wyu_001/myscrapy
接下来接着说明如何多线程运行多个爬虫脚本：
项目的根目录下有个batch.py文件，这个就是批量运行多个爬虫的脚本，这里使用了线程池，同时运行spider下的多个爬虫类，也可以在setting.py文件中设置运行的爬虫文件：

#batch
#批量运行默认情况下运行spider下继承myspider类的子类
#批量运行脚本参数定义，一次并发线程数

BATCH_THREADS =10

#batch run files in list
#自定义运行spider下脚本文件
BATCH_FILES =['dxyqueryhospital.py',
              'haodfqueryhospital.py'
              ]
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下面是batch.py脚本代码：

import inspect
from os import listdir,getcwd
from os.path import isfile,join
import importlib

from config.setting import BATCH_THREADS
from config.setting import BATCH_FILES

from concurrent.futures import ThreadPoolExecutor,as_completed

crawls=[]

lib_dir = "spider"
file_path = join(getcwd(),lib_dir)
crawl_files = [ f for f in listdir(file_path) if isfile(join(file_path,f))]

crawls_sets = set(crawl_files)
batch_sets = set(BATCH_FILES)


if len(batch_sets):
    crawl_files = list(crawls_sets.intersection(batch_sets))

for file in crawl_files:

    if file != "__init__.py" :
        file = f'.{file.split(".")[0]}'
        moudle = importlib.import_module(file,lib_dir)

        for name ,obj in inspect.getmembers(moudle,inspect.isclass):
            if obj.__base__.__name__ == "MySpider":
                crawls.append(obj())

thread_num = 0

tasks = []

with ThreadPoolExecutor(max_workers= BATCH_THREADS) as tp:

    while(len(crawls)):
        task = tp.submit(crawls.pop().start_request)
        tasks.append(task)

        thread_num += 1
        if thread_num >= BATCH_THREADS :
            for future in as_completed(tasks):
                finish = future.result()

            thread_num  = 0

    for future in as_completed(tasks):
        finish = future.result()

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