我们在访问网站的时候，发现有些网页ID 是按顺序排列的数字，这个时候我们就可以使用ID遍历的方式来爬取内容。但是局限性在于有些ID数字在10位数左右，那么这样爬取效率就会很低很低！ import itertools from common import download def iteration():     max_errors = 5 # maximum number of consecutive download errors allowed     num_errors = 0 # current number of consecutive download errors     for page in itertools.count(1):         url = 'http://example.webscraping.com/view/-{}'.format(page)         html = download(url)         if html is None:             # received an error trying to download this webpage             num_errors += 1             if num_errors == max_errors:                 # reached maximum amount of errors in a row so exit                 break             # so assume have reached the last country ID and can stop downloading         else:             # success - can scrape the result             # ...             num_errors = 0