scrapy/scrapy/exceptions.py

114 lines
2.9 KiB
Python

"""
Scrapy core exceptions
These exceptions are documented in docs/topics/exceptions.rst. Please don't add
new exceptions here without documenting them there.
"""
from __future__ import annotations
from typing import Any
# Internal
class NotConfigured(Exception):
"""Indicates a missing configuration situation"""
class _InvalidOutput(TypeError):
"""
Indicates an invalid value has been returned by a middleware's processing method.
Internal and undocumented, it should not be raised or caught by user code.
"""
# HTTP and crawling
class IgnoreRequest(Exception):
"""Indicates a decision was made not to process a request"""
class DontCloseSpider(Exception):
"""Request the spider not to be closed yet"""
class CloseSpider(Exception):
"""Raised to request the closing of the running :ref:`spider
<topics-spiders>`.
You may specify a *reason* for closing the spider. It can be an arbitrary
string, but it is a best practice to name it like a Python variable name,
for example:
.. code-block:: python
def parse(self, response):
if "Bandwidth exceeded" in response.body:
raise CloseSpider("bandwidth_exceeded")
This exception may be raised from:
- The :ref:`callbacks
<topics-request-response-ref-request-callback-arguments>` and the
:meth:`~scrapy.Spider.yield_seeds` method of spiders.
- The :meth:`~scrapy.spidermiddlewares.SpiderMiddleware.process_seeds`
method of :ref:`spider middlewares <topics-spider-middleware>`.
- :ref:`Handlers <topics-signals>` of the :signal:`spider_idle` signal.
"""
def __init__(self, reason: str = "cancelled"):
super().__init__()
self.reason = reason
class StopDownload(Exception):
"""
Stop the download of the body for a given response.
The 'fail' boolean parameter indicates whether or not the resulting partial response
should be handled by the request errback. Note that 'fail' is a keyword-only argument.
"""
def __init__(self, *, fail: bool = True):
super().__init__()
self.fail = fail
# Items
class DropItem(Exception):
"""Drop item from the item pipeline"""
def __init__(self, message: str, log_level: str | None = None):
super().__init__(message)
self.log_level = log_level
class NotSupported(Exception):
"""Indicates a feature or method is not supported"""
# Commands
class UsageError(Exception):
"""To indicate a command-line usage error"""
def __init__(self, *a: Any, **kw: Any):
self.print_help = kw.pop("print_help", True)
super().__init__(*a, **kw)
class ScrapyDeprecationWarning(Warning):
"""Warning category for deprecated features, since the default
DeprecationWarning is silenced on Python 2.7+
"""
class ContractFail(AssertionError):
"""Error raised in case of a failing contract"""