Add Distinction with Python-Patterns

Author: ELC

README.md

@@ -13,6 +13,16 @@ so on.
 Each pattern has an independent README linked below with a guide to highlight
 differences between implementation details.
 
+## Why This repo?
+
+The [python-patterns repo](https://github.com/faif/python-patterns) already
+provides a succint and clear way to implement idiomatic patterns in Python.
+
+This repo focuses on showing different ways to implement the same pattern,
+including the traditional Java/C/C# like implementation to provide the reader
+with a comparison. Moreover metrics are added to each implementation to better
+contrast solutions.
+
 ## Patterns
 
 ### Behavioural

patterns/behavioural/publish_subscribe/problem_01/__init__.py

@@ -0,0 +1,3 @@
+from .customer import Customer
+
+__all__ = ["Customer"]

patterns/behavioural/publish_subscribe/problem_01/customer/__init__.py

@@ -0,0 +1,20 @@
+from dataclasses import dataclass
+from typing import List
+
+from ..store import Store
+
+from ..product import Product
+
+
+@dataclass
+class Customer:
+    name: str
+    interests: List[Product]
+    satisfied: bool = False
+
+    def ask_for_interests(self, store: Store) -> None:
+        for product in self.interests:
+            if not store.is_available(product):
+                return
+
+        self.satisfied = True

patterns/behavioural/publish_subscribe/problem_01/customer/customer.py

@@ -0,0 +1,50 @@
+import time
+from .customer import Customer
+from .product import Product
+from .store import Store
+
+
+def main() -> None:
+    cellphone = Product("MobileX", "TechS", 300)
+    couch = Product("GiantSofa", "AllComfort", 800)
+    mug = Product("CoffeeM", "IndustrialTea", 20)
+
+    customers = [
+        Customer(name="John", interests=[cellphone]),
+        Customer(name="Mary", interests=[couch, mug]),
+        Customer(name="Alicia", interests=[cellphone, mug]),
+    ]
+
+    late_customer = Customer(name="bob", interests=[cellphone, couch, mug])
+    late_customer_arrival = 3
+
+    store = Store(name="AllYouNeed")
+
+    initial_time = time.time()
+
+    products = [cellphone, couch, mug]
+    estimated_time_arrivals = [1, 2, 4]
+
+    notification_period = 1
+
+    while True:
+        current_time = time.time() - initial_time
+
+        for product, eta in zip(products, estimated_time_arrivals):
+            if current_time >= eta and product not in store.producers:
+                store.add_product(product)
+
+        if current_time >= late_customer_arrival and late_customer not in customers:
+            customers.append(late_customer)
+
+        for customer in customers:
+            customer.ask_for_interests(store)
+
+        if all(customer.satisfied for customer in customers):
+            break
+
+        time.sleep(notification_period)
+
+
+if __name__ == "__main__":
+    main()

patterns/behavioural/publish_subscribe/problem_01/main.py

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+from .producer import Producer
+
+__all__ = ["Producer"]

patterns/behavioural/publish_subscribe/problem_01/producer/__init__.py

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+from dataclasses import dataclass, field
+from typing import List, Set
+
+from ..store import Store
+from ..product import Product
+
+
+@dataclass
+class Producer:
+    name: str
+    products: Set[Product] = field(default_factory=set)
+    stores: List[Store] = field(default_factory=list)
+
+    def is_available(self, product: Product) -> bool:
+        if product in self.products:
+            print(f"The product {product.name} is available at {self.name}")
+            return True
+
+        print(f"The product {product.name} is not available at {self.name}")
+        return False
+
+    def release_product(self, name: str, price: float) -> None:
+        new_product = Product(name=name, brand=self.name, price=price)
+        self.products.add(new_product)

patterns/behavioural/publish_subscribe/problem_01/producer/producer.py

@@ -0,0 +1,3 @@
+from .product import Product
+
+__all__ = ["Product"]

patterns/behavioural/publish_subscribe/problem_01/product/__init__.py

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+from typing import Any, NamedTuple
+
+
+class Product(NamedTuple):
+    name: str
+    brand: str
+    price: float
+
+    def __eq__(self, other: Any):
+        if not isinstance(other, Product):
+            return False
+        return other.name == self.name and other.brand == self.brand

patterns/behavioural/publish_subscribe/problem_01/product/product.py

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+from .store import Store
+
+__all__ = ["Store"]