Scrapy 抓取数据但没有输出到文件 [英] Scrapy scrapes data but no output to file
问题描述
尽管能够在scrapy shell 中成功执行大部分行，但我还是得到了空白的json 文件.当我运行命令 scrapy crawl course 时，我的课程机器人是:
I've been getting blank json files despite successfully being able to execute most of the lines in scrapy shell.
When I run the command scrapy crawl courses with my courses bot being:
from scrapy.spiders import CrawlSpider
from scrapy.linkextractors import LinkExtractor
from tutorial.items import CoursesItem
from bs4 import BeautifulSoup
import scrapy
class CoursesSpider(CrawlSpider):
name = 'courses'
allowed_domains = ['guide.berkeley.edu']
start_urls = ['http://guide.berkeley.edu/courses/ast',
]
def parse(self, response):
soup = BeautifulSoup(response.body_as_unicode(), 'lxml')
items = []
for course_info, course_desc, course_req in zip(soup.find_all('p',class_='courseblocktitle'), \
soup.find_all('p', class_='courseblockdesc'), \
soup.find_all('div', class_='course-section')):
item = CoursesItem()
item['title'] = course_info.text
item['description'] = course_desc.text
item['requirements'] = course_req.text
yield items
并通过 settings.py
and by settings.py being
BOT_NAME = 'courses'
SPIDER_MODULES = ['tutorial.spiders']
NEWSPIDER_MODULE = 'tutorial.spiders'
USER_AGENT = 'Mozilla/5.0 (Windows NT 6.1; WOW64; rv:39.0) Gecko/20100101 Firefox/39.0.3'
# ITEM_PIPELINES = {
# 'tutorial.pipelines.JsonExportPipeline': 300
# }
FEED_URI = 'output.json'
FEED_FORMAT = 'json'
正如您在评论部分所看到的，我也尝试过制作管道.我的管道文件如下所示:
As you can see in the commented section, I've also tried making a pipeline. My pipeline file looks like this:
from scrapy import signals
from scrapy.exporters import JsonLinesItemExporter
class JsonExportPipeline(object):
def __init__(self):
self.files = {}
@classmethod
def from_crawler(cls, crawler):
pipeline = cls()
crawler.signals.connect(pipeline.spider_opened, signals.spider_opened)
crawler.signals.connect(pipeline.spider_closed, signals.spider_closed)
return pipeline
def spider_opened(self, spider):
file = open('%s_spider.json' % spider.name, 'w+b')
self.files[spider] = file
self.exporter = JsonLinesItemExporter(file)
self.exporter.start_exporting()
def spider_closed(self, spider):
self.exporter.finish_exporting()
file = self.files.pop(spider)
file.close()
def process_item(self, item, spider):
self.exporter.export_item(item)
return item
但我觉得这可能不是错误所在，尽管这是可能的，因为我主要遵循了我发现的几个教程.
But I feel that might not be where the error lies although it's possible since I largely followed a couple of tutorials I found.
我使用 BeautifulSoup 来简化我选择项目的方式.
I used BeautifulSoup to simplify the way I select the items.
最后但并非最不重要的是，终端在我运行后看起来像这样.
Last but not least, the terminal looks like this after I run it.
2015-08-07 23:58:44 [scrapy] INFO: Scrapy 1.0.1 started (bot: courses)
2015-08-07 23:58:44 [scrapy] INFO: Optional features available: ssl, http11
2015-08-07 23:58:44 [scrapy] INFO: Overridden settings: {'NEWSPIDER_MODULE': 'tu
torial.spiders', 'FEED_URI': 'output.json', 'SPIDER_MODULES': ['tutorial.spiders
'], 'BOT_NAME': 'courses', 'USER_AGENT': 'Mozilla/5.0 (Windows NT 6.1; WOW64; rv
:39.0) Gecko/20100101 Firefox/39.0.3', 'FEED_FORMAT': 'json'}
2015-08-07 23:58:44 [scrapy] INFO: Enabled extensions: CloseSpider, FeedExporter
, TelnetConsole, LogStats, CoreStats, SpiderState
2015-08-07 23:58:44 [scrapy] INFO: Enabled downloader middlewares: HttpAuthMiddl
eware, DownloadTimeoutMiddleware, UserAgentMiddleware, RetryMiddleware, DefaultH
eadersMiddleware, MetaRefreshMiddleware, HttpCompressionMiddleware, RedirectMidd
leware, CookiesMiddleware, ChunkedTransferMiddleware, DownloaderStats
2015-08-07 23:58:44 [scrapy] INFO: Enabled spider middlewares: HttpErrorMiddleware, OffsiteMiddleware, RefererMiddleware, UrlLengthMiddleware, DepthMiddleware
2015-08-07 23:58:44 [scrapy] INFO: Enabled item pipelines:
2015-08-07 23:58:44 [scrapy] INFO: Spider opened
2015-08-07 23:58:44 [scrapy] INFO: Crawled 0 pages (at 0 pages/min), scraped 0 i
tems (at 0 items/min)
2015-08-07 23:58:44 [scrapy] DEBUG: Telnet console listening on 127.0.0.1:6024
2015-08-07 23:58:45 [scrapy] DEBUG: Redirecting (301) to <GET http://guide.berke
ley.edu/courses/ast/> from <GET http://guide.berkeley.edu/courses/ast>
2015-08-07 23:58:45 [scrapy] DEBUG: Crawled (200) <GET http://guide.berkeley.edu
/courses/ast/> (referer: None)
2015-08-07 23:58:45 [scrapy] INFO: Closing spider (finished)
2015-08-07 23:58:45 [scrapy] INFO: Dumping Scrapy stats:
{'downloader/request_bytes': 537,
'downloader/request_count': 2,
'downloader/request_method_count/GET': 2,
'downloader/response_bytes': 22109,
'downloader/response_count': 2,
'downloader/response_status_count/200': 1,
'downloader/response_status_count/301': 1,
'finish_reason': 'finished',
'finish_time': datetime.datetime(2015, 8, 8, 6, 58, 45, 600000),
'log_count/DEBUG': 3,
'log_count/INFO': 7,
'response_received_count': 1,
'scheduler/dequeued': 2,
'scheduler/dequeued/memory': 2,
'scheduler/enqueued': 2,
'scheduler/enqueued/memory': 2,
'start_time': datetime.datetime(2015, 8, 8, 6, 58, 44, 663000)}
2015-08-07 23:58:45 [scrapy] INFO: Spider closed (finished)
我已经彻底地运行了大部分选项.运行--parse 的单数选项告诉我我正在解析项目，但即便如此，我想知道除了解析错误修复(即输出到json)之外的地方.最终，我想将所有这些数据通过管道传输到数据库中.
I've ran most of my options thoroughly. Running the singular option of --parse tells me that I'm off in parsing the items, but even then, I'd like to know where to go beyond the parse bug fix (ie outputting to json). Ultimately, I want to pipe all this data into a database.
我知道要浏览的内容很多，但感谢您的帮助，谢谢！
I know it's a lot to look through, but any help is appreciated, thanks!
推荐答案
你写错了词.在解析函数中更改项目 -> 项目.
You write a wrong word. In parse function change items -> item.
def parse(self, response):
soup = BeautifulSoup(response.body_as_unicode(), 'lxml')
items = []
for ...
item = CoursesItem()
item['title'] = course_info.text
item['description'] = course_desc.text
item['requirements'] = course_req.text
yield items # -> item
`
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