Fixed (most) uses of cmp functions for sorting

active_projects/eop/bayes.py

@@ -71,10 +71,9 @@ class IntroducePokerHand(PiCreatureScene, SampleSpaceScene):
             card.set_height(community_cards.get_height())
 
         selected_community_cards = VGroup(*[card for card in community_cards if card.numerical_value >= 10])
-        card_cmp = lambda c1, c2 : cmp(
+        selected_community_cards.submobjects.sort(
-            c1.numerical_value, c2.numerical_value
+            key=lambda c: c.numerical_value
         )
-        selected_community_cards.submobjects.sort(card_cmp)
 
         selected_community_cards.save_state()
         for card in selected_community_cards:
@@ -84,7 +83,9 @@ class IntroducePokerHand(PiCreatureScene, SampleSpaceScene):
             you.hand.target, 
             [c.target for c in selected_community_cards]
         ))
-        straight_cards.submobjects.sort(card_cmp)
+        straight_cards.submobjects.sort(
+            key=lambda c: c.numerical_value
+        )
         straight_cards.arrange_submobjects(RIGHT, buff = SMALL_BUFF)
         straight_cards.next_to(community_cards, UP, aligned_edge = LEFT)
         you.hand.target.shift(MED_SMALL_BUFF*UP)

mobject/mobject.py

@@ -829,10 +829,7 @@ class Mobject(Container):
 
     def sort_submobjects(self, point_to_num_func=lambda p: p[0]):
         self.submobjects.sort(
-            lambda *mobs: cmp(*[
+            key=lambda m: point_to_num_func(mob.get_center())
-                point_to_num_func(mob.get_center())
-                for mob in mobs
-            ])
         )
         return self
 

old_projects/WindingNumber_G.py

@@ -2655,7 +2655,7 @@ class SearchSpacePerimeterVsArea(EquationSolver2d):
         alt_path_parts = path_parts.copy()
         size = lambda m : m.get_height() + m.get_width()
         alt_path_parts.submobjects.sort(
-            lambda m1, m2 : -cmp(size(m1), size(m2))
+            key=lambda m1: -size(m1)
         )
 
         full_rect = SurroundingRectangle(

old_projects/bell.py

@@ -2011,7 +2011,7 @@ class VennDiagramProofByContradiction(Scene):
             else:
                 rejected.append((x, y))
         rejected.sort(
-            lambda (x1, y1), (x2, y2) : (x2**2 + y2**2) - (x1**2 + y1**2)
+            kay=lambda (x, y): (x**2 + y**2)
         )
         for i in range(len(photons) - len(pairs)):
             pairs.append(rejected.pop())

old_projects/borsuk.py

@@ -21,7 +21,9 @@ class Jewel(VMobject):
         self.set_height(self.height)
         self.rotate(-np.pi/2-np.pi/24, RIGHT)        
         self.rotate(-np.pi/12, UP)
-        self.submobjects.sort(lambda m1, m2 : cmp(-m1.get_center()[2], -m2.get_center()[2]))
+        self.submobjects.sort(
+            key=lambda m: -m1.get_center()[2]
+        )
         return self
 
 class Necklace(VMobject):
@@ -210,7 +212,11 @@ class IntroduceStolenNecklaceProblem(ThreeDScene):
             self.shuffle_jewels(jewels)
         self.play(FadeOut(self.title))
         for jewel_type, label in zip(jewel_types, enumeration_labels):
-            jewel_type.submobjects.sort(lambda m1, m2: cmp(m1.get_center()[0], m2.get_center()[0]))
+            jewel_type.submobjects.sort(
+                key=
+         y=lambda m: m1.get
+        )
+            )
             jewel_type.save_state()
             jewel_type.generate_target()
             jewel_type.target.arrange_submobjects()
@@ -1298,7 +1304,9 @@ class MakeTwoJewelCaseContinuous(IntroduceStolenNecklaceProblem):
         enumeration_labels.to_edge(UP)
 
         for jewel_type, label in zip(jewel_types, enumeration_labels):
-            jewel_type.submobjects.sort(lambda m1, m2: cmp(m1.get_center()[0], m2.get_center()[0]))
+            jewel_type.submobjects.sort(
+                key=key=lambda mettr()[0]
+         
             jewel_type.save_state()
             jewel_type.generate_target()
             jewel_type.target.arrange_submobjects()
@@ -1352,7 +1360,7 @@ class MakeTwoJewelCaseContinuous(IntroduceStolenNecklaceProblem):
         self.add(chain, jewels)
 
         jewels.submobjects.sort(
-            lambda m1, m2 : cmp(m1.get_center()[0], m2.get_center()[0])
+            key=lambda m: m.get_center()[0]
         )
         remaining_indices = list(range(len(jewels)))
         remaining_indices.remove(example_index)
@@ -1362,7 +1370,7 @@ class MakeTwoJewelCaseContinuous(IntroduceStolenNecklaceProblem):
         self.remove(chain)
         segments = VGroup(example_segment[0], *remaining_segments)
         segments.submobjects.sort(
-            lambda m1, m2 : cmp(m1.get_center()[0], m2.get_center()[0])
+            key=lambda m: m.get_center()[0]
         )
         segment_types = VGroup(*[
             VGroup(*[m for m in segments if m.get_color() == Color(color)])

old_projects/div_curl.py

@@ -2365,7 +2365,7 @@ class IntroduceCurl(IntroduceVectorField):
             **self.vector_field_config
         )
         vector_field.submobjects.sort(
-            lambda v1, v2: cmp(v1.get_length(), v2.get_length())
+            key=lambda v: v.get_length()
         )
 
         self.play(LaggedStart(GrowArrow, vector_field))
@@ -2459,8 +2459,8 @@ class ShearCurl(IntroduceCurl):
         vector_field = self.vector_field = VectorField(
             self.func, **self.vector_field_config
         )
-        vector_field.submobjects.sort(
+        vector_field.submobjects.key=sort(
-            lambda a1, a2: cmp(a1.get_length(), a2.get_length())
+            key=lambda a: a.get_length()
         )
         self.play(LaggedStart(GrowArrow, vector_field))
 
@@ -2951,7 +2951,7 @@ class IllustrateGaussMagnetic(IllustrateGaussLaw):
             self.func, **self.vector_field_config
         )
         vector_field.submobjects.sort(
-            lambda a1, a2: -cmp(a1.get_length(), a2.get_length())
+            key=lambda a: -a1.get_length()
         )
         self.play(LaggedStart(GrowArrow, vector_field))
         self.add_foreground_mobjects(

old_projects/eoc/chapter3.py

@@ -1544,7 +1544,7 @@ class PowerRuleAlgebra(Scene):
             xs_copy.generate_target()
             target_list = [dx_copy.target] + list(xs_copy.target)
             target_list.sort(
-                lambda m1, m2 : cmp(m1.get_center()[0], m2.get_center()[0])
+                key=lambda m: m.get_center()[0]
             )
             dots = TexMobject("+", ".", ".", "\\dots")
             for dot_index, dot in enumerate(dots):

old_projects/eola/chapter2.py

@@ -649,7 +649,7 @@ class VectorsToDotsScene(VectorScene):
                 run_time = 3
             )
         )
-        vectors.sort(lambda v1, v2 : int(np.sign(v2.get_length() - v1.get_length())))
+        vectors.sort(key=lambda v: v.get_length())
         self.add(*vectors)
         def v_to_dot(vector):
             return Dot(vector.get_end(), fill_color = vector.get_stroke_color())

old_projects/eola/chapter9.py

@@ -1616,7 +1616,7 @@ class HowToTranslateAMatrix(Scene):
             array.top_brace = Brace(VGroup(array, her_vector), UP)
         for array in cob_matrix, inv_cob:
             submobs = array.split()
-            submobs.sort(lambda m1, m2: cmp(m1.get_center()[0], m2.get_center()[0]))
+            submobs.sort(key=lambda m: m.get_center()[0])
             array.submobjects = submobs
         her_vector.set_color(MAROON_B)
         cob_matrix.set_color_by_gradient(BLUE, MAROON_B)

old_projects/waves.py

@@ -689,7 +689,7 @@ class IntroduceElectricField(PiCreatureScene):
         ])
         shading_list = list(result)
         shading_list.sort(
-            lambda m1, m2 : cmp(m1.get_length(), m2.get_length())
+            key=lambda m: m1.get_length()
         )
         VGroup(*shading_list).set_color_by_gradient(*self.vector_field_colors)
         result.set_fill(opacity = 0.75)