diff --git a/README.md b/README.md
index 8688e02..e8f8817 100644
--- a/README.md
+++ b/README.md
@@ -1 +1 @@
-ООП и работа с API
+Netology PD-97
diff --git a/decorators/log_task_02_1.log b/decorators/log_task_02_1.log
new file mode 100644
index 0000000..f1668d7
--- /dev/null
+++ b/decorators/log_task_02_1.log
@@ -0,0 +1,38 @@
+{
+    "timestamp": "2024-04-12 16:47:00.372140",
+    "name": "hello_world",
+    "args": [],
+    "kwargs": {},
+    "result": "Hello World"
+},
+{
+    "timestamp": "2024-04-12 16:47:00.372719",
+    "name": "summator",
+    "args": [
+        2,
+        2
+    ],
+    "kwargs": {},
+    "result": 4
+},
+{
+    "timestamp": "2024-04-12 16:47:00.373231",
+    "name": "div",
+    "args": [
+        6,
+        2
+    ],
+    "kwargs": {},
+    "result": 3.0
+},
+{
+    "timestamp": "2024-04-12 16:47:00.373578",
+    "name": "summator",
+    "args": [
+        4.3
+    ],
+    "kwargs": {
+        "b": 2.2
+    },
+    "result": 6.5
+},
diff --git a/decorators/log_task_02_2.log b/decorators/log_task_02_2.log
new file mode 100644
index 0000000..f484da7
--- /dev/null
+++ b/decorators/log_task_02_2.log
@@ -0,0 +1,38 @@
+{
+    "timestamp": "2024-04-12 16:47:00.374138",
+    "name": "hello_world",
+    "args": [],
+    "kwargs": {},
+    "result": "Hello World"
+},
+{
+    "timestamp": "2024-04-12 16:47:00.375032",
+    "name": "summator",
+    "args": [
+        2,
+        2
+    ],
+    "kwargs": {},
+    "result": 4
+},
+{
+    "timestamp": "2024-04-12 16:47:00.375575",
+    "name": "div",
+    "args": [
+        6,
+        2
+    ],
+    "kwargs": {},
+    "result": 3.0
+},
+{
+    "timestamp": "2024-04-12 16:47:00.375831",
+    "name": "summator",
+    "args": [
+        4.3
+    ],
+    "kwargs": {
+        "b": 2.2
+    },
+    "result": 6.5
+},
diff --git a/decorators/log_task_02_3.log b/decorators/log_task_02_3.log
new file mode 100644
index 0000000..fc1d3d9
--- /dev/null
+++ b/decorators/log_task_02_3.log
@@ -0,0 +1,38 @@
+{
+    "timestamp": "2024-04-12 16:47:00.376093",
+    "name": "hello_world",
+    "args": [],
+    "kwargs": {},
+    "result": "Hello World"
+},
+{
+    "timestamp": "2024-04-12 16:47:00.376384",
+    "name": "summator",
+    "args": [
+        2,
+        2
+    ],
+    "kwargs": {},
+    "result": 4
+},
+{
+    "timestamp": "2024-04-12 16:47:00.376543",
+    "name": "div",
+    "args": [
+        6,
+        2
+    ],
+    "kwargs": {},
+    "result": 3.0
+},
+{
+    "timestamp": "2024-04-12 16:47:00.376698",
+    "name": "summator",
+    "args": [
+        4.3
+    ],
+    "kwargs": {
+        "b": 2.2
+    },
+    "result": 6.5
+},
diff --git a/decorators/log_task_03_1.log b/decorators/log_task_03_1.log
new file mode 100644
index 0000000..3efdeb3
--- /dev/null
+++ b/decorators/log_task_03_1.log
@@ -0,0 +1,9 @@
+{
+    "name": "new_function",
+    "timestamp": "2024-04-12 16:46:58.412284",
+    "args": [
+        "10006"
+    ],
+    "kwargs": {},
+    "result": "\u0410\u0440\u0438\u0441\u0442\u0430\u0440\u0445 \u041f\u0430\u0432\u043b\u043e\u0432"
+},
diff --git a/decorators/main.log b/decorators/main.log
new file mode 100644
index 0000000..9b6239d
--- /dev/null
+++ b/decorators/main.log
@@ -0,0 +1,48 @@
+{
+    "name": "hello_world",
+    "timestamp": "2024-04-12 16:40:02.552160",
+    "args": [],
+    "kwargs": {},
+    "result": "Hello World"
+},
+{
+    "name": "summator",
+    "timestamp": "2024-04-12 16:40:02.552166",
+    "args": [
+        2,
+        2
+    ],
+    "kwargs": {},
+    "result": 4
+},
+{
+    "name": "div",
+    "timestamp": "2024-04-12 16:40:02.552167",
+    "args": [
+        6,
+        2
+    ],
+    "kwargs": {},
+    "result": 3.0
+},
+{
+    "name": "summator",
+    "timestamp": "2024-04-12 16:40:02.552166",
+    "args": [
+        4.3
+    ],
+    "kwargs": {
+        "b": 2.2
+    },
+    "result": 6.5
+},
+{
+    "name": "summator",
+    "timestamp": "2024-04-12 16:40:02.552166",
+    "args": [],
+    "kwargs": {
+        "a": 0,
+        "b": 0
+    },
+    "result": 0
+},
diff --git a/decorators/modules/__init__.py b/decorators/modules/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/decorators/modules/client.py b/decorators/modules/client.py
new file mode 100644
index 0000000..2d97c14
--- /dev/null
+++ b/decorators/modules/client.py
@@ -0,0 +1,76 @@
+documents = [
+    {"type": "passport", "number": "2207 876234", "name": "Василий Гупкин"},
+    {"type": "invoice", "number": "11-2", "name": "Геннадий Покемонов"},
+    {"type": "insurance", "number": "10006", "name": "Аристарх Павлов"},
+    {"type": "driver license", "number": "5455 028765", "name": "Василий Иванов"},
+]
+
+directories = {
+    '1': ['2207 876234', '11-2', '5455 028765'],
+    '2': ['10006'],
+    '3': []
+}
+
+### My
+def get_name(doc_number):
+    result = "Документ не найден"
+
+    for document in documents:
+        if doc_number in document["number"]:
+            result = document["name"]
+
+    return result
+
+
+def get_directory(doc_number):
+    result = "Полки с таким документом не найдено"
+
+    for number in directories:
+        if doc_number in directories[number]:
+            result = number
+
+    return result
+
+
+def add(document_type, number, name, shelf_number):
+    new_document = {"type": document_type, "number": number, "name": name}
+    documents.append(new_document)
+
+    if shelf_number in directories:
+        if number not in directories[str(shelf_number)]:
+            directories[str(shelf_number)].append(str(number))
+    else:
+        directories[str(shelf_number)] = [str(number)]
+
+### Netology
+def get_name(doc_number):
+    for document in documents:
+        if document['number'] == doc_number:
+            return document['name']
+    return "Документ не найден"
+
+
+def get_directory(doc_number):
+    for number, docs in directories.items():
+        if doc_number in docs:
+            return number
+    return "Полки с таким документом не найдено"
+
+
+def add(document_type, number, name, shelf_number):
+    new_doc = {"type": document_type, "number": number, "name": name}
+    documents.append(new_doc)
+    if shelf_number in directories:
+        directories[shelf_number].append(number)
+    else:
+        directories[shelf_number] = [number]
+
+
+if __name__ == '__main__':
+    print(get_name("10006"))
+    print(get_directory("11-2"))
+    print(get_name("101"))
+    add('international passport', '311 020203', 'Александр Пушкин', 3)
+    print(get_directory("311 020203"))
+    print(get_name("311 020203"))
+    print(get_directory("311 020204"))
diff --git a/decorators/task_01.py b/decorators/task_01.py
new file mode 100644
index 0000000..5ae9ea5
--- /dev/null
+++ b/decorators/task_01.py
@@ -0,0 +1,77 @@
+import os
+import json
+from datetime import datetime
+
+
+def logger(old_function):
+    log_info = {}
+
+    log_info.update({
+        "name": old_function.__name__,
+        "timestamp": datetime.now()
+    })
+
+    def new_function(*args, **kwargs):
+        result = old_function(*args, **kwargs)
+
+        log_info.update({
+            "args": args,
+            "kwargs": kwargs,
+            "result": result
+        })
+
+        json_object = json.dumps(log_info, indent=4, default=str)
+
+        with open('main.log', "a+") as outfile:
+            outfile.writelines(json_object + ",\n")
+
+        return result
+
+    return new_function
+
+
+def test_1():
+    path = 'main.log'
+    if os.path.exists(path):
+        os.remove(path)
+
+    @logger
+    def hello_world():
+        return 'Hello World'
+
+    @logger
+    def summator(a, b=0):
+        return a + b
+
+    @logger
+    def div(a, b):
+        return a / b
+
+    # hello_world
+    assert 'Hello World' == hello_world(), "Функция возвращает 'Hello World'"
+
+    # summator
+    result = summator(2, 2)
+    assert isinstance(result, int), 'Должно вернуться целое число'
+    assert result == 4, '2 + 2 = 4'
+
+    # div
+    result = div(6, 2)
+    assert result == 3, '6 / 2 = 3'
+
+    # main.log
+    assert os.path.exists(path), 'файл main.log должен существовать'
+
+    summator(4.3, b=2.2)
+    summator(a=0, b=0)
+
+    with open(path) as log_file:
+        log_file_content = str(log_file.read())
+
+    assert 'summator' in log_file_content, 'должно записаться имя функции'
+    for item in (4.3, 2.2, 6.5):
+        assert str(item) in log_file_content, f'{item} должен быть записан в файл'
+
+
+if __name__ == '__main__':
+    test_1()
diff --git a/decorators/task_02.py b/decorators/task_02.py
new file mode 100644
index 0000000..52e5b44
--- /dev/null
+++ b/decorators/task_02.py
@@ -0,0 +1,73 @@
+import os
+import json
+from datetime import datetime
+
+
+def logger(path):
+    log_info = {}
+
+    def __logger(old_function):
+        def new_function(*args, **kwargs):
+            result = old_function(*args, **kwargs)
+
+            log_info.update({
+                "timestamp": datetime.now(),
+                "name": old_function.__name__,
+                "args": args,
+                "kwargs": kwargs,
+                "result": result
+            })
+
+            json_object = json.dumps(log_info, indent=4, default=str)
+
+            with open(path, "a+") as outfile:
+                outfile.writelines(json_object + ",\n")
+
+            return result
+
+        return new_function
+
+    return __logger
+
+
+def test_2():
+    paths = ('log_task_02_1.log', 'log_task_02_2.log', 'log_task_02_3.log')
+
+    for path in paths:
+        if os.path.exists(path):
+            os.remove(path)
+
+        @logger(path)
+        def hello_world():
+            return 'Hello World'
+
+        @logger(path)
+        def summator(a, b=0):
+            return a + b
+
+        @logger(path)
+        def div(a, b):
+            return a / b
+
+        assert 'Hello World' == hello_world(), "Функция возвращает 'Hello World'"
+        result = summator(2, 2)
+        assert isinstance(result, int), 'Должно вернуться целое число'
+        assert result == 4, '2 + 2 = 4'
+        result = div(6, 2)
+        assert result == 3, '6 / 2 = 3'
+        summator(4.3, b=2.2)
+
+    for path in paths:
+        assert os.path.exists(path), f'файл {path} должен существовать'
+
+        with open(path) as log_file:
+            log_file_content = str(log_file.read())
+
+        assert 'summator' in log_file_content, 'должно записаться имя функции'
+
+        for item in (4.3, 2.2, 6.5):
+            assert str(item) in log_file_content, f'{item} должен быть записан в файл'
+
+
+if __name__ == '__main__':
+    test_2()
\ No newline at end of file
diff --git a/decorators/task_03.py b/decorators/task_03.py
new file mode 100644
index 0000000..2c52a84
--- /dev/null
+++ b/decorators/task_03.py
@@ -0,0 +1,50 @@
+import os
+import json
+from datetime import datetime
+from modules.client import get_name
+
+
+def logger(old_function):
+    log_info = {}
+
+    log_info.update({
+        "name": old_function.__name__,
+        "timestamp": datetime.now()
+    })
+
+    def new_function(*args, **kwargs):
+        result = old_function(*args, **kwargs)
+
+        log_info.update({
+            "args": args,
+            "kwargs": kwargs,
+            "result": result
+        })
+
+        json_object = json.dumps(log_info, indent=4, default=str)
+
+        with open('log_task_03_1.log', "a+") as outfile:
+            outfile.writelines(json_object + ",\n")
+
+        return result
+
+    return new_function
+
+
+def main():
+    path = 'log_task_03_1.log'
+
+    if os.path.exists(path):
+        os.remove(path)
+
+    @logger
+    def new_function(name):
+        result = get_name(name)
+
+        return result
+
+    print(new_function("10006"))
+
+
+if __name__ == '__main__':
+    main()
diff --git a/iterators_generators_yield/solution.py b/iterators_generators_yield/solution.py
new file mode 100644
index 0000000..7c7e3f6
--- /dev/null
+++ b/iterators_generators_yield/solution.py
@@ -0,0 +1,214 @@
+import types
+from itertools import chain
+
+
+# _________________________
+# task 1
+
+class FlatIteratorV1:
+
+    def __init__(self, list_of_list):
+        self.list_of_list = list_of_list
+
+    def __iter__(self):
+        self.cursor_inner = -1
+        self.cursor_outer = 0
+        return self
+
+    def __next__(self):
+        self.cursor_inner += 1
+        if self.cursor_inner >= len(self.list_of_list[self.cursor_outer]):
+            self.cursor_outer += 1
+            self.cursor_inner = 0
+        if self.cursor_outer >= len(self.list_of_list):
+            raise StopIteration
+        return self.list_of_list[self.cursor_outer][self.cursor_inner]
+
+
+class FlatIteratorV2:
+
+    def __init__(self, list_of_list):
+        self.list_of_list = list_of_list
+
+    def __iter__(self):
+        self.iterators = iter(iter(l) for l in self.list_of_list)
+        self.current_iter = next(self.iterators)
+        return self
+
+    def __next__(self):
+        try:
+            next_item = next(self.current_iter)
+        except StopIteration:
+            self.current_iter = next(self.iterators)
+            next_item = next(self.current_iter)
+        return next_item
+
+
+class FlatIteratorV3:
+
+    def __init__(self, list_of_list):
+        self.list_of_list = list_of_list
+
+    def __iter__(self):
+        self.flat_iter = chain.from_iterable(self.list_of_list)
+        return self
+
+    def __next__(self):
+        return next(self.flat_iter)
+
+
+class FlatIteratorV4:
+
+    def __init__(self, list_of_list):
+        self.list_of_list = list_of_list
+
+    def __iter__(self):
+        return chain.from_iterable(self.list_of_list)
+
+
+# _________________________
+# task 2
+
+def flat_generator_v1(list_of_lists):
+    for inner_list in list_of_lists:
+        for item in inner_list:
+            yield item
+
+
+def flat_generator_v2(list_of_lists):
+    for inner_list in list_of_lists:
+        yield from inner_list
+
+
+def flat_generator_v3(list_of_lists):
+    for item in chain.from_iterable(list_of_lists):
+        yield item
+
+
+def flat_generator_v4(list_of_lists):
+    return (item for item in chain.from_iterable(list_of_lists))
+
+# _________________________
+# task 3
+
+
+class FlatIteratorHard:
+
+    def __init__(self, list_of_list):
+        self.list_of_list = list_of_list
+
+    def __iter__(self):
+        self.iters_stack = [iter(self.list_of_list)]
+        return self
+
+    def __next__(self):
+        while self.iters_stack:
+            try:
+                next_item = next(self.iters_stack[-1])
+                #  пытаемся получить следующий элемент
+            except StopIteration:
+                self.iters_stack.pop()
+                #  если не получилось, значит итератор пустой
+                continue
+
+            if isinstance(next_item, list):
+                # если следующий элемент оказался списком, то
+                # добавляем его итератор в стек
+                self.iters_stack.append(iter(next_item))
+
+            else:
+                return next_item
+        raise StopIteration
+
+# _________________________
+# task 4
+
+
+def flat_generator_v5(list_of_list):
+    for i in list_of_list:
+        if isinstance(i, list):
+            for j in flat_generator_v5(i):
+                yield j
+        else:
+            yield i
+
+
+def test_task_1():
+
+    list_of_lists_1 = [
+        ['a', 'b', 'c'],
+        ['d', 'e', 'f', 'h', False],
+        [1, 2, None]
+    ]
+
+    for IteratorClass in (FlatIteratorV1, FlatIteratorV2, FlatIteratorV3, FlatIteratorV4):
+
+        for flat_iterator_item, check_item in zip(
+                IteratorClass(list_of_lists_1),
+                ['a', 'b', 'c', 'd', 'e', 'f', 'h', False, 1, 2, None]
+        ):
+            assert flat_iterator_item == check_item
+
+        assert list(IteratorClass(list_of_lists_1)) == ['a', 'b', 'c', 'd', 'e', 'f', 'h', False, 1, 2, None]
+
+
+def test_task_2():
+
+    list_of_lists_1 = [
+        ['a', 'b', 'c'],
+        ['d', 'e', 'f', 'h', False],
+        [1, 2, None]
+    ]
+
+    for yield_function in (flat_generator_v1, flat_generator_v2, flat_generator_v3, flat_generator_v4):
+
+        for flat_iterator_item, check_item in zip(
+                yield_function(list_of_lists_1),
+                ['a', 'b', 'c', 'd', 'e', 'f', 'h', False, 1, 2, None]
+        ):
+            assert flat_iterator_item == check_item
+
+        assert list(yield_function(list_of_lists_1)) == ['a', 'b', 'c', 'd', 'e', 'f', 'h', False, 1, 2, None]
+
+        assert isinstance(yield_function(list_of_lists_1), types.GeneratorType)
+
+
+def test_task_3():
+    list_of_lists_2 = [
+        [['a'], ['b', 'c']],
+        ['d', 'e', [['f'], 'h'], False],
+        [1, 2, None, [[[[['!']]]]], []]
+    ]
+    for flat_iterator_item, check_item in zip(
+            FlatIteratorHard(list_of_lists_2),
+            ['a', 'b', 'c', 'd', 'e', 'f', 'h', False, 1, 2, None, '!']
+    ):
+        assert flat_iterator_item == check_item
+
+    assert list(FlatIteratorHard(list_of_lists_2)) == ['a', 'b', 'c', 'd', 'e', 'f', 'h', False, 1, 2, None, '!']
+
+
+def test_task_4():
+    list_of_lists_2 = [
+        [['a'], ['b', 'c']],
+        ['d', 'e', [['f'], 'h'], False],
+        [1, 2, None, [[[[['!']]]]], []]
+    ]
+
+    for flat_iterator_item, check_item in zip(
+            flat_generator_v5(list_of_lists_2),
+            ['a', 'b', 'c', 'd', 'e', 'f', 'h', False, 1, 2, None, '!']
+    ):
+        assert flat_iterator_item == check_item
+
+    assert list(flat_generator_v5(list_of_lists_2)) == ['a', 'b', 'c', 'd', 'e', 'f', 'h', False, 1, 2, None, '!']
+
+    assert isinstance(flat_generator_v5(list_of_lists_2), types.GeneratorType)
+
+
+if __name__ == '__main__':
+
+    test_task_1()
+    test_task_2()
+    test_task_3()
+    test_task_4()