Merge pull request UWPCE-PythonCert#83 from imdavis/master

Session 07 Assignment: Circle Class

Author: codedragon

Students/imdavis/session07/circle.py

@@ -16,22 +16,28 @@ def radius(self):
 
     @radius.setter
     def radius(self, radius):
-        assert radius > 0, "radius must be nonzero and non-negative"
-        self.__radius = radius
+        if radius <= 0:
+            raise ValueError("radius must be nonzero and non-negative")
+        else:
+            self.__radius = radius
 
     @classmethod
     def from_diameter(cls, diameter):
-        assert diameter > 0, "diameter must be nonzero and non-negative"
-        return cls(diameter / 2.0)
+        if diameter <= 0:
+            raise ValueError("diameter must be nonzero and non-negative")
+        else:
+            return cls(diameter / 2.0)
 
     @property
     def diameter(self):
         return self.radius * 2.0
 
     @diameter.setter
     def diameter(self, value):
-        assert value > 0, "diameter must be nonzero and non-negative"
-        self.radius = value / 2.0
+        if value <= 0:
+            raise ValueError("diameter must be nonzero and non-negative")
+        else:
+            self.radius = value / 2.0
 
     @property
     def area(self):

Students/imdavis/session07/test_circle.py

@@ -123,27 +123,27 @@ def test_nonsense_radius():
     Make sure we can't create a Circle object with a negative or zero 
     radius.
     """
-    with pytest.raises(AssertionError):
+    with pytest.raises(ValueError):
         c = Circle(-1.234)
-    with pytest.raises(AssertionError):
+    with pytest.raises(ValueError):
         c = Circle(0)
     c = Circle(1.234)
-    with pytest.raises(AssertionError):
+    with pytest.raises(ValueError):
         c.radius = -1.234 
-    with pytest.raises(AssertionError):
+    with pytest.raises(ValueError):
         c.radius = 0
 
 def test_nonsense_diameter():
     """
     Make sure we can't create a Circle object with a negative or zero 
     diameter.
     """
-    with pytest.raises(AssertionError):
+    with pytest.raises(ValueError):
         c = Circle.from_diameter(-2.468)
-    with pytest.raises(AssertionError):
+    with pytest.raises(ValueError):
         c = Circle.from_diameter(0)
     c = Circle.from_diameter(2.468)
-    with pytest.raises(AssertionError):
+    with pytest.raises(ValueError):
         c.diameter = -2.468
-    with pytest.raises(AssertionError):
+    with pytest.raises(ValueError):
         c.diameter = 0