Cleanup and minor improvements to instance initialization.

Author: Arjan Egges

1 - coupling and cohesion/coupling-cohesion-after.py

@@ -2,10 +2,7 @@
 import random
 
 class VehicleInfo:
-    brand: str
-    electric: bool
-    catalogue_price: int
-
+    
     def __init__(self, brand, electric, catalogue_price):
         self.brand = brand
         self.electric = electric
@@ -22,9 +19,6 @@ def print(self):
         print(f"Payable tax: {self.compute_tax()}")
 
 class Vehicle:
-    id: str
-    license_plate: str
-    info: VehicleInfo
 
     def __init__(self, id, license_plate, info):
         self.id = id
@@ -39,18 +33,15 @@ def print(self):
 
 class VehicleRegistry:
 
-    vehicle_info = { }
-
-    def add_vehicle_info(self, brand, electric, catalogue_price):
-        self.vehicle_info[brand] = VehicleInfo(brand, electric, catalogue_price)
-
-
     def __init__(self):
+        self.vehicle_info = { }
         self.add_vehicle_info("Tesla Model 3", True, 60000)
         self.add_vehicle_info("Volkswagen ID3", True, 35000)
         self.add_vehicle_info("BMW 5", False, 45000)
         self.add_vehicle_info("Tesla Model Y", True, 75000)
 
+    def add_vehicle_info(self, brand, electric, catalogue_price):
+        self.vehicle_info[brand] = VehicleInfo(brand, electric, catalogue_price)
 
     def generate_vehicle_id(self, length):
         return ''.join(random.choices(string.ascii_uppercase, k=length))

5 - unit testing/vehicle_info_after.py

@@ -1,7 +1,4 @@
 class VehicleInfo:
-    brand: str
-    electric: bool
-    catalogue_price: int
 
     def __init__(self, brand, electric, catalogue_price):
         self.brand = brand

5 - unit testing/vehicle_info_before.py

@@ -1,7 +1,4 @@
 class VehicleInfo:
-    brand: str
-    electric: bool
-    catalogue_price: int
 
     def __init__(self, brand, electric, catalogue_price):
         self.brand = brand

6 - template method & bridge/trading-after.py

@@ -2,6 +2,7 @@
 from typing import List
 
 class TradingBot(ABC):
+    
     def connect(self):
         print(f"Connecting to Crypto exchange...")
 
@@ -29,6 +30,7 @@ def should_sell(self, prices: List[float]) -> bool:
         pass
 
 class AverageTrader(TradingBot):
+
     def list_average(self, l: List[float]) -> float:
         return sum(l) / len(l)
 

6 - template method & bridge/trading-before.py

@@ -2,8 +2,6 @@
 
 class Application:
 
-    trading_strategy: str
-
     def __init__(self, trading_strategy = "average"):
         self.trading_strategy = trading_strategy
 

6 - template method & bridge/with-bridge.py

@@ -25,7 +25,6 @@ def get_market_data(self, coin: str) -> List[float]:
         return [10, 12, 18, 20]
 
 
-
 class TradingBot(ABC):
 
     def __init__(self, exchange: Exchange):

8 - mvc/mvc-after.py

@@ -6,6 +6,12 @@ class Model:
     def __init__(self):
         self.uuid = []
 
+    def append(self, item):
+        self.uuid.append(item)
+
+    def clear(self):
+        self.uuid = []
+
 class Controller:
     def __init__(self, model, view):
         self.model = model
@@ -17,12 +23,13 @@ def start(self):
 
     def handle_click_generate_uuid(self):
         # generate a uuid and add it to the list
-        self.model.uuid.append(uuid.uuid4())
-        self.view.append_to_list(self.model.uuid[-1])
+        newid = uuid.uuid4()
+        self.model.append(newid)
+        self.view.append_to_list(newid)
 
     def handle_click_clear_list(self):
         # clear the uuid list in the model and the view
-        self.model.uuid = []
+        self.model.clear()
         self.view.clear_list()
 
 class View(ABC):

9 - solid/dependency-inversion-after.py

@@ -1,10 +1,12 @@
 from abc import ABC, abstractmethod
 
 class Order:
-    items = []
-    quantities = []
-    prices = []
-    status = "open"
+
+    def __init__(self):
+        self.items = []
+        self.quantities = []
+        self.prices = []
+        self.status = "open"
 
     def add_item(self, name, quantity, price):
         self.items.append(name)
@@ -25,7 +27,8 @@ def is_authorized(self) -> bool:
 
 class Authorizer_SMS(Authorizer):
 
-    authorized = False
+    def __init__(self):
+        self.authorized = False
 
     def verify_code(self, code):
         print(f"Verifying SMS code {code}")
@@ -36,7 +39,8 @@ def is_authorized(self) -> bool:
 
 class Authorizer_Google(Authorizer):
 
-    authorized = False
+    def __init__(self):
+        self.authorized = False
 
     def verify_code(self, code):
         print(f"Verifying Google auth code {code}")
@@ -47,7 +51,8 @@ def is_authorized(self) -> bool:
 
 class Authorizer_Robot(Authorizer):
 
-    authorized = False
+    def __init__(self):
+        self.authorized = False
 
     def not_a_robot(self):
         self.authorized = True

9 - solid/dependency-inversion-before.py

@@ -1,10 +1,12 @@
 from abc import ABC, abstractmethod
 
 class Order:
-    items = []
-    quantities = []
-    prices = []
-    status = "open"
+
+    def __init__(self):
+        self.items = []
+        self.quantities = []
+        self.prices = []
+        self.status = "open"
 
     def add_item(self, name, quantity, price):
         self.items.append(name)
@@ -19,7 +21,8 @@ def total_price(self):
 
 class SMSAuthorizer:
 
-    authorized = False
+    def __init__(self):
+        self.authorized = False
 
     def verify_code(self, code):
         print(f"Verifying SMS code {code}")

9 - solid/interface-segregation-after-comp.py

@@ -1,10 +1,12 @@
 from abc import ABC, abstractmethod
 
 class Order:
-    items = []
-    quantities = []
-    prices = []
-    status = "open"
+
+    def __init__(self):
+        self.items = []
+        self.quantities = []
+        self.prices = []
+        self.status = "open"
 
     def add_item(self, name, quantity, price):
         self.items.append(name)
@@ -19,7 +21,8 @@ def total_price(self):
 
 class SMSAuthorizer:
 
-    authorized = False
+    def __init__(self):
+        self.authorized = False
 
     def verify_code(self, code):
         print(f"Verifying SMS code {code}")

9 - solid/interface-segregation-after.py

@@ -1,10 +1,12 @@
 from abc import ABC, abstractmethod
 
 class Order:
-    items = []
-    quantities = []
-    prices = []
-    status = "open"
+
+    def __init__(self):
+        self.items = []
+        self.quantities = []
+        self.prices = []
+        self.status = "open"
 
     def add_item(self, name, quantity, price):
         self.items.append(name)

9 - solid/interface-segregation-before.py

@@ -1,10 +1,12 @@
 from abc import ABC, abstractmethod
 
 class Order:
-    items = []
-    quantities = []
-    prices = []
-    status = "open"
+
+    def __init__(self):
+        self.items = []
+        self.quantities = []
+        self.prices = []
+        self.status = "open"
 
     def add_item(self, name, quantity, price):
         self.items.append(name)

9 - solid/liskov-substitution-after.py

@@ -1,10 +1,12 @@
 from abc import ABC, abstractmethod
 
 class Order:
-    items = []
-    quantities = []
-    prices = []
-    status = "open"
+
+    def __init__(self):
+        self.items = []
+        self.quantities = []
+        self.prices = []
+        self.status = "open"
 
     def add_item(self, name, quantity, price):
         self.items.append(name)

9 - solid/liskov-substitution-before.py

@@ -1,10 +1,12 @@
 from abc import ABC, abstractmethod
 
 class Order:
-    items = []
-    quantities = []
-    prices = []
-    status = "open"
+
+    def __init__(self):
+        self.items = []
+        self.quantities = []
+        self.prices = []
+        self.status = "open"
 
     def add_item(self, name, quantity, price):
         self.items.append(name)

9 - solid/open-closed-after.py

@@ -1,10 +1,12 @@
 from abc import ABC, abstractmethod
 
 class Order:
-    items = []
-    quantities = []
-    prices = []
-    status = "open"
+
+    def __init__(self):
+        self.items = []
+        self.quantities = []
+        self.prices = []
+        self.status = "open"
 
     def add_item(self, name, quantity, price):
         self.items.append(name)

9 - solid/open-closed-before.py

@@ -1,8 +1,10 @@
 class Order:
-    items = []
-    quantities = []
-    prices = []
-    status = "open"
+
+    def __init__(self):
+        self.items = []
+        self.quantities = []
+        self.prices = []
+        self.status = "open"
 
     def add_item(self, name, quantity, price):
         self.items.append(name)

9 - solid/single-responsibility-after.py

@@ -1,8 +1,10 @@
 class Order:
-    items = []
-    quantities = []
-    prices = []
-    status = "open"
+
+    def __init__(self):
+        self.items = []
+        self.quantities = []
+        self.prices = []
+        self.status = "open"
 
     def add_item(self, name, quantity, price):
         self.items.append(name)

9 - solid/single-responsibility-before.py

@@ -1,8 +1,10 @@
 class Order:
-    items = []
-    quantities = []
-    prices = []
-    status = "open"
+
+    def __init__(self):
+        self.items = []
+        self.quantities = []
+        self.prices = []
+        self.status = "open"
 
     def add_item(self, name, quantity, price):
         self.items.append(name)