Merge branch 'adrian' into 'master'

TopLevel (tk => root) passed

See merge request flatland/flatland!75

examples/simple_example_3.py

@@ -2,7 +2,7 @@ import random
 
 import numpy as np
 
-from flatland.envs.generators import random_rail_generator, complex_rail_generator
+from flatland.envs.generators import random_rail_generator
 from flatland.envs.observations import TreeObsForRailEnv
 from flatland.envs.rail_env import RailEnv
 from flatland.utils.rendertools import RenderTool

flatland/utils/graphics_pil.py

@@ -75,6 +75,7 @@ class PILGL(GraphicsLayer):
         self.ltAgentColors = [self.rgb_s2i(sColor) for sColor in sColors.split("#")]
         self.nAgentColors = len(self.ltAgentColors)
 
+        self.window_root = None
         self.window_open = False
         self.firstFrame = True
         self.create_layers()
@@ -131,7 +132,9 @@ class PILGL(GraphicsLayer):
         assert self.window_open is False, "Window is already open!"
         # use tk.Toplevel() instead of tk.Tk()
         # https://stackoverflow.com/questions/26097811/image-pyimage2-doesnt-exist
-        self.window = tk.Toplevel()
+        self.window_root = tk.Tk()
+        self.window_root.withdraw()
+        self.window = tk.Toplevel(self.window_root)
         self.window.title("Flatland")
         self.window.configure(background='grey')
         self.window_open = True
@@ -140,6 +143,8 @@ class PILGL(GraphicsLayer):
         self.panel.destroy()
         self.window.quit()
         self.window.destroy()
+        self.window_root.destroy()
+        self.window = None
 
     def text(self, *args, **kwargs):
         pass

tests/test_environments.py

@@ -107,7 +107,6 @@ def test_rail_environment_single_agent():
             if prev_pos != pos:
                 valid_active_actions_done += 1
 
-
         # After 6 movements on this railway network, the train should be back
         # to its original height on the map.
         assert (initial_pos[0] == agent.position[0])
@@ -124,8 +123,10 @@ def test_rail_environment_single_agent():
                 _, _, dones, _ = rail_env.step({0: action})
                 done = dones['__all__']
 
+
 test_rail_environment_single_agent()
 
+
 def test_dead_end():
     transitions = Grid4Transitions([])