Initial commit

Solutions/5_4/typedproperty.py

@@ -0,0 +1,33 @@
+# typedproperty.py
+
+def typedproperty(name, expected_type):
+    private_name = '_' + name
+
+    @property
+    def value(self):
+        return getattr(self, private_name)
+
+    @value.setter
+    def value(self, val):
+        if not isinstance(val, expected_type):
+            raise TypeError(f'Expected {expected_type}')
+        setattr(self, private_name, val)
+
+    return value
+
+
+String = lambda name: typedproperty(name, str)
+Integer = lambda name: typedproperty(name, int)
+Float = lambda name: typedproperty(name, float)
+
+# Example
+if __name__ == '__main__':
+    class Stock:
+        name = String('name')
+        shares = Integer('shares')
+        price = Float('price')
+        def __init__(self, name, shares, price):
+            self.name = name
+            self.shares = shares
+            self.price = price
+