Scrapy 请求返回 NotImplementedError答案

【问题标题】：Scrapy request returns NotImplementedErrorScrapy 请求返回 NotImplementedError
【发布时间】：2017-07-17 20:59:30
【问题描述】：

我的scrapy代码不起作用，我不明白为什么。我刚刚开始抓取，所以我现在并不关心哪个网站。我知道该问题与我选择的网址无关。

这是我的代码：

import scrapy

class Twitter(scrapy.Spider):
    name = "twitter_following"
    start_urls = ['https://www.digitalocean.com']

【问题讨论】：

您能否展示更多实际复制您遇到的错误的代码？该代码未提供您指定的错误。
无论何时您在开发者论坛上提供故障排除情况...您应该知道我们是一群顽固的类型，因为您需要对您的问题有一个完整而详细的报告，至于未实现的错误，当您错误地构建蜘蛛时会引发此错误，因为它未被识别.... ..ETC。请更新您的答案>

标签： python scrapy

【解决方案1】：

$ cat so.py 
import scrapy

class Twitter(scrapy.Spider):
    name = "twitter_following"
    start_urls = ['https://www.digitalocean.com']

$ scrapy runspider so.py 
2017-07-17 14:55:24 [scrapy.utils.log] INFO: Scrapy 1.4.0 started (bot: scrapybot)
(...)
2017-07-17 14:55:24 [scrapy.core.engine] DEBUG: Crawled (200) <GET https://www.digitalocean.com> (referer: None)
2017-07-17 14:55:24 [scrapy.core.scraper] ERROR: Spider error processing <GET https://www.digitalocean.com> (referer: None)
Traceback (most recent call last):
  File "/home/paul/.virtualenvs/scrapy14/lib/python3.6/site-packages/twisted/internet/defer.py", line 653, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
  File "/home/paul/.virtualenvs/scrapy14/lib/python3.6/site-packages/scrapy/spiders/__init__.py", line 90, in parse
    raise NotImplementedError
NotImplementedError
2017-07-17 14:55:25 [scrapy.core.engine] INFO: Closing spider (finished)
2017-07-17 14:55:25 [scrapy.statscollectors] INFO: Dumping Scrapy stats:
{'downloader/request_bytes': 218,
 'downloader/request_count': 1,
 'downloader/request_method_count/GET': 1,
 'downloader/response_bytes': 18321,
 'downloader/response_count': 1,
 'downloader/response_status_count/200': 1,
 'finish_reason': 'finished',
 'finish_time': datetime.datetime(2017, 7, 17, 12, 55, 25, 20602),
 'log_count/DEBUG': 2,
 'log_count/ERROR': 1,
 'log_count/INFO': 7,
 'memusage/max': 47943680,
 'memusage/startup': 47943680,
 'response_received_count': 1,
 'scheduler/dequeued': 1,
 'scheduler/dequeued/memory': 1,
 'scheduler/enqueued': 1,
 'scheduler/enqueued/memory': 1,
 'spider_exceptions/NotImplementedError': 1,
 'start_time': datetime.datetime(2017, 7, 17, 12, 55, 24, 131159)}
2017-07-17 14:55:25 [scrapy.core.engine] INFO: Spider closed (finished)

你需要定义一个parse callback：这是Request对象中没有引用回调时的默认回调。

$ cat so.py 
import scrapy

class Twitter(scrapy.Spider):
    name = "twitter_following"
    start_urls = ['https://www.digitalocean.com']

    def parse(self, response):
        self.logger.debug('callback "parse": got response %r' % response)
$ scrapy runspider so.py 
2017-07-17 14:58:15 [scrapy.utils.log] INFO: Scrapy 1.4.0 started (bot: scrapybot)
(...)
2017-07-17 14:58:16 [scrapy.core.engine] DEBUG: Crawled (200) <GET https://www.digitalocean.com> (referer: None)
2017-07-17 14:58:16 [twitter_following] DEBUG: callback "parse": got response <200 https://www.digitalocean.com>
2017-07-17 14:58:16 [scrapy.core.engine] INFO: Closing spider (finished)
2017-07-17 14:58:16 [scrapy.statscollectors] INFO: Dumping Scrapy stats:
{'downloader/request_bytes': 218,
 'downloader/request_count': 1,
 'downloader/request_method_count/GET': 1,
 'downloader/response_bytes': 18321,
 'downloader/response_count': 1,
 'downloader/response_status_count/200': 1,
 'finish_reason': 'finished',
 'finish_time': datetime.datetime(2017, 7, 17, 12, 58, 16, 482262),
 'log_count/DEBUG': 3,
 'log_count/INFO': 7,
 'memusage/max': 47771648,
 'memusage/startup': 47771648,
 'response_received_count': 1,
 'scheduler/dequeued': 1,
 'scheduler/dequeued/memory': 1,
 'scheduler/enqueued': 1,
 'scheduler/enqueued/memory': 1,
 'start_time': datetime.datetime(2017, 7, 17, 12, 58, 15, 609825)}
2017-07-17 14:58:16 [scrapy.core.engine] INFO: Spider closed (finished)

【讨论】：