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5bf733b6f6
default logging by making log more readable in the default case, for both Scraped and Dropped lines. Projects can still customize how items are represented by overriding the item's __str__ method, as usual.
83 lines
1.9 KiB
Python
83 lines
1.9 KiB
Python
"""
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Scrapy Item
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See documentation in docs/topics/item.rst
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"""
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from pprint import pformat
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from UserDict import DictMixin
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from scrapy.utils.trackref import object_ref
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class BaseItem(object_ref):
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"""Base class for all scraped items."""
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pass
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class Field(dict):
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"""Container of field metadata"""
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class ItemMeta(type):
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def __new__(mcs, class_name, bases, attrs):
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fields = {}
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new_attrs = {}
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for n, v in attrs.iteritems():
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if isinstance(v, Field):
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fields[n] = v
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else:
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new_attrs[n] = v
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cls = type.__new__(mcs, class_name, bases, new_attrs)
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cls.fields = cls.fields.copy()
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cls.fields.update(fields)
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return cls
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class DictItem(DictMixin, BaseItem):
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fields = {}
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def __init__(self, *args, **kwargs):
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self._values = {}
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if args or kwargs: # avoid creating dict for most common case
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for k, v in dict(*args, **kwargs).iteritems():
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self[k] = v
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def __getitem__(self, key):
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return self._values[key]
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def __setitem__(self, key, value):
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if key in self.fields:
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self._values[key] = value
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else:
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raise KeyError("%s does not support field: %s" % \
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(self.__class__.__name__, key))
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def __delitem__(self, key):
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del self._values[key]
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def __getattr__(self, name):
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if name in self.fields:
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raise AttributeError("Use item[%r] to get field value" % name)
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raise AttributeError(name)
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def __setattr__(self, name, value):
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if not name.startswith('_'):
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raise AttributeError("Use item[%r] = %r to set field value" % \
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(name, value))
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super(DictItem, self).__setattr__(name, value)
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def keys(self):
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return self._values.keys()
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def __repr__(self):
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return pformat(dict(self))
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class Item(DictItem):
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__metaclass__ = ItemMeta
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