SOLID: Final QA

Author: bzaczynski

solid-principles-python/file_manager_srp.py

@@ -4,49 +4,43 @@
 # Bad example
 # class FileManager:
 #     def __init__(self, filename):
-#         self.filename = Path(filename)
+#         self.path = Path(filename)
 
-#     def read(self):
-#         with self.filename.open(mode="r") as file:
-#             data = file.read()
-#         return data
+#     def read(self, encoding="utf-8"):
+#         return self.path.read_text(encoding)
 
-#     def write(self, data):
-#         with self.filename.open(mode="w") as file:
-#             file.write(data)
+#     def write(self, data, encoding="utf-8"):
+#         self.path.write_text(data, encoding)
 
 #     def compress(self):
-#         with ZipFile(self.filename.stem + ".zip", mode="w") as archive:
-#             archive.write(self.filename)
+#         with ZipFile(self.path.with_suffix(".zip"), mode="w") as archive:
+#             archive.write(self.path)
 
-#     def decompress(self, archive_name):
-#         with ZipFile(archive_name, mode="r") as archive:
+#     def decompress(self):
+#         with ZipFile(self.path.with_suffix(".zip"), mode="r") as archive:
 #             archive.extractall()
 
 
 # Good example
 class FileManager:
     def __init__(self, filename):
-        self.filename = Path(filename)
+        self.path = Path(filename)
 
-    def read(self):
-        with self.filename.open(mode="r") as file:
-            data = file.read()
-        return data
+    def read(self, encoding="utf-8"):
+        return self.path.read_text(encoding)
 
-    def write(self, data):
-        with self.filename.open(mode="w") as file:
-            file.write(data)
+    def write(self, data, encoding="utf-8"):
+        self.path.write_text(data, encoding)
 
 
 class ZipFileManager:
     def __init__(self, filename):
-        self.filename = Path(filename)
+        self.path = Path(filename)
 
     def compress(self):
-        with ZipFile(self.filename.stem + ".zip", mode="w") as archive:
-            archive.write(self.filename)
+        with ZipFile(self.path.with_suffix(".zip"), mode="w") as archive:
+            archive.write(self.path)
 
-    def decompress(self, archive_name):
-        with ZipFile(archive_name, mode="r") as archive:
+    def decompress(self):
+        with ZipFile(self.path.with_suffix(".zip"), mode="r") as archive:
             archive.extractall()

solid-principles-python/shapes_lsp.py

@@ -1,26 +1,44 @@
-class Rectangle:
+from abc import ABC, abstractmethod
+
+# Bad example
+# class Rectangle:
+#     def __init__(self, width, height):
+#         self.width = width
+#         self.height = height
+
+#     def calculate_area(self):
+#         return self.width * self.height
+
+
+# class Square(Rectangle):
+#     def __init__(self, side):
+#         super().__init__(side, side)
+
+#     def __setattr__(self, key, value):
+#         super().__setattr__(key, value)
+#         if key in ("width", "height"):
+#             self.__dict__["width"] = value
+#             self.__dict__["height"] = value
+
+# Good example
+class Shape(ABC):
+    @abstractmethod
+    def calculate_area(self):
+        pass
+
+
+class Rectangle(Shape):
     def __init__(self, width, height):
         self.width = width
         self.height = height
 
-    def area(self):
+    def calculate_area(self):
         return self.width * self.height
 
-    def perimeter(self):
-        return 2 * (self.width + self.height)
 
-
-class Square(Rectangle):
+class Square(Shape):
     def __init__(self, side):
-        super().__init__(side, side)
         self.side = side
 
-    @property
-    def side(self):
-        return self._side
-
-    @side.setter
-    def side(self, value):
-        self._side = value
-        self.width = value
-        self.height = value
+    def calculate_area(self):
+        return self.side ** 2