Restore Python 3.8 support

scrapy/_classutilities.py

@@ -0,0 +1,94 @@
+# https://github.com/david-salac/classutilities/issues/1
+# Unmodified copy of
+# https://github.com/david-salac/classutilities/blob/a6e4a86331936d432afaa454ed4c963528165a61/src/classutilities/classproperty.py
+
+# Allows creating a class level property
+from typing import Any, Callable
+
+
+class ClassPropertyContainer:
+    """
+    Allows creating a class level property (functionality for
+    decorator).
+    """
+
+    def __init__(self, prop_get: Any, prop_set: Any = None):
+        """
+        Container that allows having a class property decorator.
+        :param prop_get: Class property getter.
+        :param prop_set: Class property setter.
+        """
+        self.prop_get: Any = prop_get
+        self.prop_set: Any = prop_set
+
+    def __get__(self, obj: Any, cls: type = None) -> Callable:
+        """
+        Get the property getter.
+        :param obj: Instance of the class.
+        :param cls: Type of the class.
+        :return: Class property getter.
+        """
+        if cls is None:
+            cls = type(obj)
+        return self.prop_get.__get__(obj, cls)()
+
+    def __set__(self, obj, value) -> Callable:
+        """
+        Get the property setter.
+        :param obj: Instance of the class.
+        :param value: A value to be set.
+        :return: Class property setter.
+        """
+        if not self.prop_set:
+            raise AttributeError("cannot set attribute")
+        _type: type = type(obj)
+        if _type == ClassPropertyMetaClass:
+            _type = obj
+        return self.prop_set.__get__(obj, _type)(value)
+
+    def setter(self, func: Callable) -> "ClassPropertyContainer":
+        """
+        Allows creating setter in a property like way.
+        :param func: Getter function.
+        :return: Setter object for the decorator.
+        """
+        if not isinstance(func, (classmethod, staticmethod)):
+            func = classmethod(func)
+        self.prop_set = func
+        return self
+
+
+def classproperty(func):
+    """
+    Create a decorator for a class level property.
+    :param func: This class method is decorated.
+    :return: Modified class method behaving like a class property.
+    """
+    if not isinstance(func, (classmethod, staticmethod)):
+        # The method must be a classmethod (or staticmethod)
+        func = classmethod(func)
+    return ClassPropertyContainer(func)
+
+
+class ClassPropertyMetaClass(type):
+    """
+    Metaclass that allows creating a standard setter.
+    """
+
+    def __setattr__(self, key, value):
+        """Overloads setter for class"""
+        if key in self.__dict__:
+            obj = self.__dict__.get(key)
+        if obj and type(obj) is ClassPropertyContainer:
+            return obj.__set__(self, value)
+
+        return super().__setattr__(key, value)
+
+
+class ClassPropertiesMixin(metaclass=ClassPropertyMetaClass):
+    """
+    This mixin allows using class properties setter (getter works
+    correctly even without this mixin)
+    """
+
+    pass

scrapy/core/scraper.py

@@ -24,12 +24,12 @@ from typing import (
 )
 from warnings import warn
 
-from classutilities import ClassPropertiesMixin, classproperty
 from itemadapter import is_item
 from twisted.internet.defer import Deferred, inlineCallbacks
 from twisted.python.failure import Failure
 
 from scrapy import Spider, signals
+from scrapy._classutilities import ClassPropertiesMixin, classproperty
 from scrapy.core.spidermw import SpiderMiddlewareManager
 from scrapy.exceptions import (
     CloseSpider,

setup.py

@@ -7,7 +7,6 @@ version = (Path(__file__).parent / "scrapy/VERSION").read_text("ascii").strip()
 
 install_requires = [
     "Twisted>=18.9.0",
-    "classutilities>=0.2.1",
     "cryptography>=36.0.0",
     "cssselect>=0.9.1",
     "itemloaders>=1.0.1",

tox.ini

@@ -97,7 +97,6 @@ commands =
 [pinned]
 basepython = python3.8
 deps =
-    classutilities==0.2.1
     cryptography==36.0.0
     cssselect==0.9.1
     h2==3.0