#26 - Python

Author: cesarleroy

Roadmap/26 - SOLID SRP/python/CesarCarmona30.py

@@ -0,0 +1,137 @@
+'''
+  EJERCICIO
+'''
+
+# Incorrecto
+
+class User:
+  
+  def __init__(self, name, email) -> None:
+    self.name = name
+    self.email = email
+
+  def save_to_database(self):
+    pass
+
+  def send_email(self):
+    pass
+
+
+# Correcto
+
+class User:
+  
+  def __init__(self, name, email) -> None:
+    self.name = name
+    self.email = email
+
+class UserService:
+
+  def save_to_database(self, user):
+    pass
+
+class EmailService:
+  
+  def send_email(self, email, message):
+    pass
+
+'''
+  EXTRA
+'''
+
+# Incorrecto
+
+class Library:
+  def __init__(self) -> None:
+    self.books = []
+    self.users = []
+    self.loans = []
+
+  def add_book(self, title, author, copies):
+    self.books.append({"title": title, "author": author, "copies": copies})
+
+  def add_user(self, name, id, email):
+    self.users.append({"id": id, "name": name, "email": email})
+
+  def loan_book(self, user_id, book_title):
+    for book in self.books:
+      if book["title"] == book_title and book["copies"] > 0:
+        book["copies"] -= 1
+        self.loans.append(
+          {"user_id": user_id, "book_title": book_title})
+        return True
+    return False
+  
+  def return_book(self, user_id, book_title):
+    for loan in self.loans:
+      if loan["user_id"] == user_id and loan["book_title"] == book_title:
+        self.loans.remove(loan)
+        for book in self.books:
+          if book["title"] == book_title:
+            book["copies"] += 1
+          return True
+    return False
+  
+# Correcto
+
+class Book:
+
+  def __init__(self, title, author, copies):
+    self.title = title
+    self.author = author
+    self.copies = copies
+
+class User:
+
+  def __init__(self, name, id, email):
+    self.name = name
+    self.id = id
+    self.email = email
+
+class Loan:
+
+  def __init__(self):
+    self.loans = []
+
+  def loan_bool(self, user, book):
+    if book.copies > 0:
+      book.copies -= 1
+      self.loans.append(
+        {"user_id": user.id, "book_title": book.title})
+      return True
+    return False
+  
+  def return_book(self, user, book):
+    for loan in self.loans:
+      if loan["user_id"] == user.id and loan["book_title"] == book.title:
+        self.loans.remove(loan)
+        book.copies += 1
+        return True
+    return False
+  
+class Library:
+
+  def __init__(self) -> None:
+    self.books = []
+    self.users = []
+    self.loans_service = Loan()
+
+  def add_book(self, book):
+    self.books.append(book)
+
+  def add_user(self, user):
+    self.users.append(user)
+
+  def loan_book(self, user_id, book_title):
+    user = next((u for u in self.users if u.id == user_id), None)
+    book = next((b for b in self.books if b.title == book_title), None)
+    if user and book:
+      return self.loans_service.loan_book(user, book)
+    return False
+  
+  def return_book(self, user_id, book_title):
+    user = next((u for u in self.users if u.id == user_id), None)
+    book = next((b for b in self.books if b.title == book_title), None)
+    if user and book:
+      return self.loans_service.return_book(user, book)
+    return False