scrapy.utils.deprecate

Constant	`DEPRECATION_RULES`	Undocumented
Function	`_clspath`	Undocumented
Function	`attribute`	Undocumented
Function	`create_deprecated_class`	No summary
Function	`method_is_overridden`	Return True if a method named `method_name` of a `base_class` is overridden in a `subclass`.
Function	`update_classpath`	Update a deprecated path from an object with its new location

DEPRECATION_RULES: list =

Undocumented

Value

[('scrapy.telnet.', 'scrapy.extensions.telnet.')]

def _clspath(cls, forced=None):

Undocumented

def attribute(obj, oldattr, newattr, version='0.12'):

Undocumented

def create_deprecated_class(name, new_class, clsdict=None, warn_category=ScrapyDeprecationWarning, warn_once=True, old_class_path=None, new_class_path=None, subclass_warn_message='{cls} inherits from deprecated class {old}, please inherit from {new}.', instance_warn_message='{cls} is deprecated, instantiate {new} instead.'):

Return a "deprecated" class that causes its subclasses to issue a warning. Subclasses of new_class are considered subclasses of this class. It also warns when the deprecated class is instantiated, but do not when its subclasses are instantiated.

It can be used to rename a base class in a library. For example, if we have

class OldName(SomeClass):

# ...

and we want to rename it to NewName, we can do the following:

class NewName(SomeClass):
    # ...

OldName = create_deprecated_class('OldName', NewName)

Then, if user class inherits from OldName, warning is issued. Also, if some code uses issubclass(sub, OldName) or isinstance(sub(), OldName) checks they'll still return True if sub is a subclass of NewName instead of OldName.

def method_is_overridden(subclass, base_class, method_name):

Return True if a method named method_name of a base_class is overridden in a subclass.

>>> class Base:
...     def foo(self):
...         pass
>>> class Sub1(Base):
...     pass
>>> class Sub2(Base):
...     def foo(self):
...         pass
>>> class Sub3(Sub1):
...     def foo(self):
...         pass
>>> class Sub4(Sub2):
...     pass
>>> method_is_overridden(Sub1, Base, 'foo')
False
>>> method_is_overridden(Sub2, Base, 'foo')
True
>>> method_is_overridden(Sub3, Base, 'foo')
True
>>> method_is_overridden(Sub4, Base, 'foo')
True

def update_classpath(path):

Update a deprecated path from an object with its new location