Add code for eight seminar

08_python/README.md

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+### Практика про классы в питоне
+
+Что здесь есть полезного?
+- [descriptor](./descriptor) -- про модификаторы и как использовать `@property`;
+- [mro](./mro) -- method resolution order или примеры про плату за сомнительные решения;
+- [definition](./definition) -- определения классов;
+- [magic](./magic) -- куча примеров магических методов;
+- [mixins](./mixins) -- пример паттерна mixin;
+- [class-deco](./class-deco) -- как использовать класс в качестве декоратора;
+- [dataclasses](./dataclasses) -- датаклассы (классы без методов, но только с
+данными);

08_python/class-deco/getter.py

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+class ClassDeco:
+    def __init__(self, f):
+        self.f = f
+
+    def __call__(self, *args, **kwargs):
+        print(self.f, args, kwargs)
+        return self.f(*args, **kwargs)
+
+
+@ClassDeco
+def foo():
+    return 45
+
+
+# foo = ClassDeco(foo)

08_python/dataclasses/dcls.py

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+from dataclasses import dataclass
+from typing import Union
+
+
+#  def dataclass(cls=None, /, *, init=True, repr=True, eq=True, order=False,
+#                unsafe_hash=False, frozen=False):
+#      """Returns the same class as was passed in, with dunder methods
+#      added based on the fields defined in the class.
+#
+#      Examines PEP 526 __annotations__ to determine fields.
+#
+#      If init is true, an __init__() method is added to the class. If
+#      repr is true, a __repr__() method is added. If order is true, rich
+#      comparison dunder methods are added. If unsafe_hash is true, a
+#      __hash__() method function is added. If frozen is true, fields may
+#      not be assigned to after instance creation.
+#      """
+
+
+@dataclass(frozen=True)
+class A:
+    a: int
+    b: bool
+    c: str = "asd"
+    f: Union[int, bool, str] = 0
+
+    def foo(self):
+        print(self)

08_python/definition/cl_defo.py

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+class A:
+    pass
+
+
+class C:
+    a, b = 1, 1
+    for i in range(15):
+        a, b = b, a + b
+
+    print(a)
+    f = lambda self, a: a
+    g = lambda self, a: self.f(a)
+
+    def __init__(self, x, y):
+        print(self)
+        self.x = x
+        self.y = y

08_python/definition/dct.py

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+class A:
+    n = 5
+    e = 50
+    f = lambda self: 42
+
+    def __init__(self):
+        self.a = 1000

08_python/definition/def_cls.py

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+class C:
+    f = 50
+
+    a, b = 1, 1
+    for _ in range(10):
+        a, b = b, a + b
+    print(a, b)
+
+    def __init__(self, a, b):
+        print(self)
+        self.a = a
+        self.b = b

08_python/definition/inheritance.py

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+# class Base(object)
+class Base:
+    def foo(self):
+        return 42
+
+
+class NotBase:
+    def foo(self):
+        return 43
+
+
+class A(NotBase, Base):
+    def bar(self):
+        return 41

08_python/descriptor/modifiers.py

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+class A:
+    def __init__(self, a, b):
+        self._a = a
+        self.__b = b
+
+    @property
+    def super_duper_var(self):
+        print(self)
+        return self.__b
+
+    @super_duper_var.setter
+    def super_duper_var(self, value):
+        self.__b = value
+
+    # @super_duper_var.deleter
+    # def super_duper_var(self):
+    #     pass

08_python/magic/MyHashable.py

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+from abc import ABC
+
+
+class MyHashable(ABC):
+    @classmethod
+    def __subclasshook__(cls, sbcls):
+        hash_func = getattr(sbcls, "__hash__", None)
+        return hash_func is not None

08_python/magic/always_field.py

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+class AlwaysHaveField:
+    def __getattr__(self, value):
+        return value

08_python/magic/ex_for.py

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+class Iterator:
+    def __init__(self, origin_list):
+        self._ref = origin_list
+        self.n = -1
+
+    def __next__(self):
+        if self.n < len(self._ref) - 1:
+            self.n += 1
+            return self._ref[self.n]
+        raise StopIteration()
+
+
+class A:
+    def __init__(self):
+        self.a = [1, 2, 3, 4]
+
+    def __iter__(self):
+        return Iterator(self.a)
+
+
+a = A()
+for el in a:
+    print(el)

08_python/magic/ex_for2.py

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+class A:
+    def __init__(self):
+        self.a = [1, 2, 3, 4]
+
+    def __getitem__(self, ind):
+        return self.a[ind]
+
+
+a = A()
+for el in a:
+    print(el)

08_python/magic/hasheq.py

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+class MADATA:
+    def __init__(
+        self,
+        a: int,
+        b: int,
+        c: int,
+    ):
+        self.a = a
+        self.b = b
+        self.c = c
+
+    @property
+    def _tup_view(self):
+        return self.a, self.b, self.c
+
+    def __hash__(self):
+        return hash(self._tup_view)
+
+    def __eq__(self, o):
+        return isinstance(o, type(self)) and o._tup_view == self._tup_view

08_python/magic/new_getattr.py

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+class A:
+    def __init__(self):
+        self.a = 1
+        self.b = 2
+
+    def foo(self):
+        print("Hello")
+
+    def __getattr__(self, name):
+        print(f"Called __getattr__ with arg: {name}")
+        return name

08_python/magic/nmp.py

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+class DF:
+    def __getitem__(self, key):
+        return key
+
+    def __setitem__(self, key, value):
+        print(key, value)

08_python/mixins/cat_girl.py

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+class GirlsMixin:
+    def hooray(self):
+        print("Hoooray")
+
+
+class CatMixin:
+    def feed(self, hp):
+        print("Meow")
+
+
+class CatGirls(GirlsMixin, CatMixin):
+    def main(self):
+        super().feed(50)
+        super().hooray()

08_python/mixins/completely_f_cked.py

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+class Base:
+    def __init__(self, a):
+        self.x = a
+
+
+class A(Base):
+    def __init__(self):
+        super().__init__(5)
+
+
+class B(Base):
+    def __init__(self, x):
+        super().__init__(x)
+
+
+class C(A, B):
+    ...
+
+
+class D(B, A):
+    ...

08_python/mro/broken_mro.py

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+class Base:
+    def foo(self):
+        print("Base")
+
+
+class A(Base):
+    def foo(self):
+        print("A")
+        super().foo()
+
+
+class B(Base):
+    def foo(self):
+        print("B")
+        super().foo()
+
+
+class C(A, B):
+    def foo(self):
+        print("C")
+        super().foo()
+
+
+class D(B, A):
+    def foo(self):
+        print("D")
+        super().foo()
+
+
+class E(C, D):
+    pass
+
+
+print("HEELLO")

08_python/mro/mro.py

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+class Base:
+    def foo(self):
+        print("Base")
+
+
+class A(Base):
+    def foo(self):
+        print("A")
+        super().foo()
+
+
+class B(Base):
+    def foo(self):
+        print("B")
+        super().foo()
+
+
+class C(A, B):
+    def foo(self):
+        print("C")
+        super().foo()
+
+
+print("HEELLO")