#29 - python

Author: duendeintemporal

Roadmap/29 - SOLID ISP/python/duendeintemporal.py

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+#29 { Retos para Programadores } Principio SOLID de Segregación de Interfaces (Interface Segregation Principle, ISP) 
+
+# Bibliography reference:
+# The Web Development Glossary (Jens Oliver Meiert) (Z-Library)
+# I use GPT as a reference and sometimes to correct or generate proper comments.
+
+"""  
+* EJERCICIO:
+ * Explora el "Principio SOLID de Segregación de Interfaces
+ * (Interface Segregation Principle, ISP)", y crea un ejemplo
+ * simple donde se muestre su funcionamiento de forma correcta e incorrecta.
+ *
+ * DIFICULTAD EXTRA (opcional):
+ * Crea un gestor de impresoras.
+ * Requisitos:
+ * 1. Algunas impresoras sólo imprimen en blanco y negro.
+ * 2. Otras sólo a color.
+ * 3. Otras son multifunción, pueden imprimir, escanear y enviar fax.
+ * Instrucciones:
+ * 1. Implementa el sistema, con los diferentes tipos de impresoras y funciones.
+ * 2. Aplica el ISP a la implementación.
+ * 3. Desarrolla un código que compruebe que se cumple el principio.
+ """
+
+""" Interface Segregation Principle
+The principle that no client should be forced to depend on methods it does
+not use. ISP splits interfaces that are very large into smaller and more
+specific ones so that clients will only have to know about the methods that
+are of interest to them. Such shrunken interfaces are also called role
+interfaces. ISP is intended to keep a system decoupled and thus easier to
+refactor, change, and redeploy.  """
+
+
+# Shorthan for print
+log = print
+
+# Incorrect Example
+
+class PaymentService:
+    def process_credit_card_payment(self, amount):
+        pass
+
+    def process_paypal_payment(self, amount):
+        pass
+
+    def process_bitcoin_payment(self, amount):
+        pass
+
+
+class CreditCardPayment(PaymentService):
+    def process_credit_card_payment(self, amount):
+        log(f"Processing credit card payment of {amount}")
+
+    def process_paypal_payment(self, amount):
+        raise Exception("This payment method does not support PayPal payments")
+
+    def process_bitcoin_payment(self, amount):
+        raise Exception("This payment method does not support Bitcoin payments")
+
+
+class PayPalPayment(PaymentService):
+    def process_credit_card_payment(self, amount):
+        raise Exception("This payment method does not support credit card payments")
+
+    def process_paypal_payment(self, amount):
+        log(f"Processing PayPal payment of {amount}")
+
+    def process_bitcoin_payment(self, amount):
+        raise Exception("This payment method does not support Bitcoin payments")
+
+
+class BitcoinPayment(PaymentService):
+    def process_credit_card_payment(self, amount):
+        raise Exception("This payment method does not support credit card payments")
+
+    def process_paypal_payment(self, amount):
+        raise Exception("This payment method does not support PayPal payments")
+
+    def process_bitcoin_payment(self, amount):
+        log(f"Processing Bitcoin payment of {amount}")
+
+
+# Example usage
+credit_card_payment = CreditCardPayment()
+credit_card_payment.process_credit_card_payment(250)  # Processing credit card payment of 250
+# credit_card_payment.process_paypal_payment(87)  # This will raise an exception
+# Exception: This payment method does not support PayPal payments
+
+# Correct Example
+
+class CreditCardPaymentService:
+    def process_credit_card_payment(self, amount):
+        print(f"Processing credit card payment of {amount}")
+
+
+class PayPalPaymentService:
+    def process_paypal_payment(self, amount):
+        print(f"Processing PayPal payment of {amount}")
+
+
+class BitcoinPaymentService:
+    def process_bitcoin_payment(self, amount):
+        print(f"Processing Bitcoin payment of {amount}")
+
+
+# Example usage
+credit_card_payment1 = CreditCardPaymentService()
+credit_card_payment1.process_credit_card_payment(400)  # Processing credit card payment of 400
+
+pay_pal_payment = PayPalPaymentService()
+pay_pal_payment.process_paypal_payment(130)  # Processing PayPal payment of 130
+
+bitcoin_payment = BitcoinPaymentService()
+bitcoin_payment.process_bitcoin_payment(0.020)  # Processing Bitcoin payment of 0.02
+
+
+# Extra Difficulty Exercise
+
+class BlackAndWhitePrinter:
+    def print(self, doc):
+        print(f"Printing: {doc} in Black & White")
+
+
+class ColorPrinter:
+    def print(self, doc):
+        print(f"Printing: {doc} in Color")
+
+
+class MultiFunctionPrinter:
+    def print_in_black_and_white(self, doc):
+        print(f"Printing: {doc} in Black & White")
+
+    def print(self, doc):
+        print(f"Printing: {doc} in Color")
+
+    def fax(self, doc):
+        print(f"Faxing: {doc}")
+
+    def scan(self, doc):
+        print(f"Scanning: {doc}")
+
+
+# Example usage for printers
+book = 'vuelointemporal.odt'
+
+bw_printer = BlackAndWhitePrinter()
+bw_printer.print(book)  # Printing: vuelointemporal.odt in Black & White
+
+c_printer = ColorPrinter()
+c_printer.print(book)  # Printing: vuelointemporal.odt in Color
+
+m_printer = MultiFunctionPrinter()
+m_printer.print_in_black_and_white(book)  # Printing: vuelointemporal.odt in Black & White
+m_printer.print(book)  # Printing: vuelointemporal.odt in Color
+m_printer.fax(book)  # Faxing: vuelointemporal.odt
+m_printer.scan(book)  # Scanning: vuelointemporal.odt