Final exam version with mass and speed

solar_objects.py

@@ -3,11 +3,12 @@ import random
 
 
 class SpaceObject:
-    def __init__(self, x, y, radius, color):
+    def __init__(self, x, y, radius, color, mass=1.0):
         self.x = x
         self.y = y
         self.radius = radius
         self.color = color
+        self.mass = mass
 
     def update(self):
         pass
@@ -17,8 +18,8 @@ class SpaceObject:
 
 
 class Star(SpaceObject):
-    def __init__(self, x, y, radius=34, color=(255, 185, 40), name="Star"):
-        super().__init__(x, y, radius, color)
+    def __init__(self, x, y, radius=34, color=(255, 185, 40), name="Star", mass=1.989e30):
+        super().__init__(x, y, radius, color, mass)
         self.name = name
         self.planets = []
 
@@ -46,13 +47,15 @@ class Star(SpaceObject):
 
 
 class Planet(SpaceObject):
-    def __init__(self, star, orbit_number, orbit_radius, angle, speed, direction, radius=None, color=None):
+    def __init__(self, star, orbit_number, orbit_radius, angle, speed, direction, radius=None, color=None, mass=None):
         self.star = star
         self.orbit_number = orbit_number
         self.orbit_radius = orbit_radius
         self.angle = angle
         self.speed = speed
+        self.angular_speed = speed
         self.direction = direction
+        self.linear_speed = abs(self.angular_speed * self.orbit_radius)
 
         if radius is None:
             radius = random.randint(8, 13)
@@ -64,8 +67,11 @@ class Planet(SpaceObject):
                 random.randint(90, 255),
             )
 
+        if mass is None:
+            mass = random.uniform(3.0e24, 8.0e24)
+
         x, y = self.calculate_position()
-        super().__init__(x, y, radius, color)
+        super().__init__(x, y, radius, color, mass)
 
     def calculate_position(self):
         x = self.star.x + math.cos(self.angle) * self.orbit_radius
@@ -73,7 +79,7 @@ class Planet(SpaceObject):
         return x, y
 
     def update(self):
-        self.angle += self.speed * self.direction
+        self.angle += self.angular_speed * self.direction
         self.x, self.y = self.calculate_position()
 
     def draw_orbit(self, screen, pygame):