Merge branch 'master' of github.com:3b1b/manim into video-work

manimlib/mobject/mobject.py

@@ -82,6 +82,14 @@ class Mobject(object):
     def __str__(self):
         return self.__class__.__name__
 
+    def __add__(self, other : 'Mobject') -> 'Mobject':
+        assert(isinstance(other, Mobject))
+        return self.get_group_class()(self, other)
+
+    def __mul__(self, other : 'int') -> 'Mobject':
+        assert(isinstance(other, int))
+        return self.replicate(other)
+
     def init_data(self):
         self.data = {
             "points": np.zeros((0, 3)),
@@ -1609,6 +1617,10 @@ class Group(Mobject):
             raise Exception("All submobjects must be of type Mobject")
         Mobject.__init__(self, **kwargs)
         self.add(*mobjects)
+        
+    def __add__(self, other : 'Mobject' or 'Group'):
+        assert(isinstance(other, Mobject))
+        return self.add(other)
 
 
 class Point(Mobject):

manimlib/mobject/types/vectorized_mobject.py

@@ -999,6 +999,10 @@ class VGroup(VMobject):
             raise Exception("All submobjects must be of type VMobject")
         super().__init__(**kwargs)
         self.add(*vmobjects)
+    
+    def __add__(self:'VGroup', other : 'VMobject' or 'VGroup'):
+        assert(isinstance(other, VMobject))
+        return self.add(other)
 
 
 class VectorizedPoint(Point, VMobject):