diff --git a/lesson_7.py b/lesson_7.py
new file mode 100644
index 0000000..2cf35a4
--- /dev/null
+++ b/lesson_7.py
@@ -0,0 +1,238 @@
+'''
+class MyClass:
+    def __init__(self, param):
+        self.param = param
+
+    def __add__(self, other):
+        return MyClass(self.param + other.param)
+
+    def __str__(self):
+        return f"object with param ({self.param})"
+
+    def __del__(self):
+        print(f"deleting object {self.param} of MyClass")
+
+
+mc_1 = MyClass("concatenate ")
+mc_2 = MyClass("text")
+print(mc_1 + mc_2)
+
+
+
+
+class MyClass:
+    def __setattr__(self, attr, value):
+        self.__dict__[attr] = value
+
+
+mc = MyClass()
+mc.width = 40
+mc.defence = 35
+print(mc.width)
+print(mc.defence)
+
+
+
+
+class Class1:
+    def __init__(self, param):
+        self.param = param
+
+    def __call__(self, newparam):
+        self.param = newparam
+
+    def __str__(self):
+        return str(self.param)
+
+
+class Class2:
+    def __init__(self, *args):
+        self.my_list = []
+        for el in args:
+            self.my_list.append(Class1(el))
+
+    def __getitem__(self, index):
+        return self.my_list[index]
+
+
+my_obj = Class2(10, True, "text")
+print(my_obj.my_list[1])
+print(my_obj[1])
+
+
+
+class MyClass:
+    def __init__(self):
+        self.x = 40
+
+    def __eq__(self, y):
+        return self.x == y
+
+
+mc = MyClass()
+print(mc == 40)
+
+
+
+class Parent:
+    def __init__(self):
+        print("rawr parent")
+
+    def my_method(self):
+        print("parent method")
+
+
+class Child(Parent):
+    def __init__(self):
+        print("child")
+        super().__init__()
+
+    def my_method(self):
+        print("child method")
+        super().my_method()
+
+
+c = Child()
+c.my_method()
+
+
+class Iterator:
+    def __init__(self, start=0):
+        self.i = start - 1
+
+    def __iter__(self):
+        return self
+
+    def __next__(self):
+        self.i += 1
+        if self.i <= 5:
+            return self.i
+        else:
+            raise StopIteration
+
+
+obj = Iterator(2)
+for el in obj:
+    print(el)
+
+
+
+class Auto:
+    def __init__(self, year):
+        self.year = year
+
+    @property
+    def year(self):
+        return self.__year
+
+    @year.setter
+    def year(self, year):
+        if year < 2000:
+            self.__year = 2000
+        elif year > 2019:
+            self.__year = 2019
+        else:
+            self.__year = year
+
+    def get_auto_year(self):
+        return f"auto in {str(self.year)}"
+
+
+a = Auto(2090)
+print(a.get_auto_year())
+'''
+
+#1
+
+
+class Matrix:
+    def __init__(self, user_matrix):
+        self.user_matrix = user_matrix
+
+    def __str__(self):
+        return '\n'.join([' '.join([str(elem) for elem in line]) for line in self.user_matrix])
+
+    def __add__(self, other):
+        total = ''
+        if len(self.user_matrix) == len(other.user_matrix):
+            for line1, line2 in zip(self.user_matrix, other.user_matrix):
+                if len(line1) != len(line2):
+                    return "please type correct size of matrix"
+
+                matrix_line = [x + y for x, y in zip(line1, line2)]
+                total += ' '.join([str(i) for i in matrix_line]) + '\n'
+        else:
+            return "please type correct size of matrix"
+        return total
+
+
+p_1 = Matrix([[1, 2], [3, 4], [5, 6]])
+p_2 = Matrix([[3, 4], [2, 1], [9, 2]])
+print(p_1 + p_2)
+
+#2
+
+from abc import ABC, abstractmethod
+
+
+class Clothes(ABC):
+    def __init__(self, parameter):
+        self.parameter = parameter
+
+    @abstractmethod
+    def calculate(self):
+        pass
+
+
+class Coat(Clothes):
+
+    @property
+    def calculate(self):
+        return round((self.parameter / 6.5) + 0.5)
+
+
+class Costume(Clothes):
+
+    @property
+    def calculate(self):
+        return round((2 * self.parameter) + 0.3)
+
+
+coat = Coat(30)
+costume = Costume(120)
+print(coat.calculate)
+print(costume.calculate)
+
+#3
+
+
+class Cage:
+    def __init__(self, nums):
+        self.nums = nums
+
+    def orders(self, rows):
+        return '\n'.join(['*' * rows for _ in range(self.nums // rows)]) + '\n' + '*' * (self.nums % rows)
+
+    def __str__(self):
+        return str(self.nums)
+
+    def __add__(self, other):
+        return str(self.nums + other.nums)
+
+    def __sub__(self, other):
+        return self.nums - other.nums if self.nums - other.nums > 0 \
+            else "too much dots on second cage or they're equal"
+
+    def __mul__(self, other):
+        return str(self.nums * other.nums)
+
+    def __truediv__(self, other):
+        return self.nums / other.nums if other.nums != 0 \
+            else "you cannot divide on 0"
+
+
+cage_1 = Cage(20)
+cage_2 = Cage(40)
+print(cage_1)
+print(cage_1 + cage_2)
+print(cage_1.orders(5))