mirror of https://github.com/scrapy/scrapy.git
122 lines
3.9 KiB
Python
122 lines
3.9 KiB
Python
"""
|
|
Base class for Scrapy spiders
|
|
|
|
See documentation in docs/topics/spiders.rst
|
|
"""
|
|
|
|
from __future__ import annotations
|
|
|
|
import logging
|
|
from typing import TYPE_CHECKING, Any, Dict, Iterable, List, Optional, Union, cast
|
|
|
|
from twisted.internet.defer import Deferred
|
|
|
|
from scrapy import signals
|
|
from scrapy.http import Request, Response
|
|
from scrapy.utils.trackref import object_ref
|
|
from scrapy.utils.url import url_is_from_spider
|
|
|
|
if TYPE_CHECKING:
|
|
from collections.abc import Callable
|
|
|
|
# typing.Concatenate requires Python 3.10
|
|
# typing.Self requires Python 3.11
|
|
from typing_extensions import Concatenate, Self
|
|
|
|
from scrapy.crawler import Crawler
|
|
from scrapy.settings import BaseSettings, _SettingsKeyT
|
|
from scrapy.utils.log import SpiderLoggerAdapter
|
|
|
|
CallbackT = Callable[Concatenate[Response, ...], Any]
|
|
|
|
|
|
class Spider(object_ref):
|
|
"""Base class for scrapy spiders. All spiders must inherit from this
|
|
class.
|
|
"""
|
|
|
|
name: str
|
|
custom_settings: Optional[Dict[_SettingsKeyT, Any]] = None
|
|
|
|
def __init__(self, name: Optional[str] = None, **kwargs: Any):
|
|
if name is not None:
|
|
self.name: str = name
|
|
elif not getattr(self, "name", None):
|
|
raise ValueError(f"{type(self).__name__} must have a name")
|
|
self.__dict__.update(kwargs)
|
|
if not hasattr(self, "start_urls"):
|
|
self.start_urls: List[str] = []
|
|
|
|
@property
|
|
def logger(self) -> SpiderLoggerAdapter:
|
|
from scrapy.utils.log import SpiderLoggerAdapter
|
|
|
|
logger = logging.getLogger(self.name)
|
|
return SpiderLoggerAdapter(logger, {"spider": self})
|
|
|
|
def log(self, message: Any, level: int = logging.DEBUG, **kw: Any) -> None:
|
|
"""Log the given message at the given log level
|
|
|
|
This helper wraps a log call to the logger within the spider, but you
|
|
can use it directly (e.g. Spider.logger.info('msg')) or use any other
|
|
Python logger too.
|
|
"""
|
|
self.logger.log(level, message, **kw)
|
|
|
|
@classmethod
|
|
def from_crawler(cls, crawler: Crawler, *args: Any, **kwargs: Any) -> Self:
|
|
spider = cls(*args, **kwargs)
|
|
spider._set_crawler(crawler)
|
|
return spider
|
|
|
|
def _set_crawler(self, crawler: Crawler) -> None:
|
|
self.crawler: Crawler = crawler
|
|
self.settings: BaseSettings = crawler.settings
|
|
crawler.signals.connect(self.close, signals.spider_closed)
|
|
|
|
def start_requests(self) -> Iterable[Request]:
|
|
if not self.start_urls and hasattr(self, "start_url"):
|
|
raise AttributeError(
|
|
"Crawling could not start: 'start_urls' not found "
|
|
"or empty (but found 'start_url' attribute instead, "
|
|
"did you miss an 's'?)"
|
|
)
|
|
for url in self.start_urls:
|
|
yield Request(url, dont_filter=True)
|
|
|
|
def _parse(self, response: Response, **kwargs: Any) -> Any:
|
|
return self.parse(response, **kwargs)
|
|
|
|
if TYPE_CHECKING:
|
|
parse: CallbackT
|
|
else:
|
|
|
|
def parse(self, response: Response, **kwargs: Any) -> Any:
|
|
raise NotImplementedError(
|
|
f"{self.__class__.__name__}.parse callback is not defined"
|
|
)
|
|
|
|
@classmethod
|
|
def update_settings(cls, settings: BaseSettings) -> None:
|
|
settings.setdict(cls.custom_settings or {}, priority="spider")
|
|
|
|
@classmethod
|
|
def handles_request(cls, request: Request) -> bool:
|
|
return url_is_from_spider(request.url, cls)
|
|
|
|
@staticmethod
|
|
def close(spider: Spider, reason: str) -> Union[Deferred, None]:
|
|
closed = getattr(spider, "closed", None)
|
|
if callable(closed):
|
|
return cast(Union[Deferred, None], closed(reason))
|
|
return None
|
|
|
|
def __repr__(self) -> str:
|
|
return f"<{type(self).__name__} {self.name!r} at 0x{id(self):0x}>"
|
|
|
|
|
|
# Top-level imports
|
|
from scrapy.spiders.crawl import CrawlSpider, Rule
|
|
from scrapy.spiders.feed import CSVFeedSpider, XMLFeedSpider
|
|
from scrapy.spiders.sitemap import SitemapSpider
|