Initialize grid and node classes. Initialize main window.

UI/grid.py

@@ -0,0 +1,34 @@
+import pygame
+
+
+class Grid:
+    def __init__(self, game):
+        self.game = game
+        self.length = self.game.screen_res[0]/15
+        self.width = (self.game.screen_res[1]/15)-3
+
+        self.nodes = [[Node(self, [row, col + 3]) 
+                      for row in xrange(self.length)]
+                      for col in xrange(self.width)]
+
+
+class Node:
+    def __init__(self, grid, pos):
+        self.grid = grid
+        self.game = self.grid.game
+
+        self.pos = pos
+        self.blit_pos = [i*15 for i in self.pos]
+        self.color = [0, 0, 0]
+
+        self.image = pygame.Surface((15, 15))
+
+        self.rect = self.image.get_rect(topleft=self.blit_pos)
+
+        self.solid = 0
+        self.in_path = False
+        self.checked = False
+
+    def fill(self, screen):
+        self.image.fill(self.color)
+        screen.blit(self.image, self.rect)

main.py

@@ -1,2 +1,12 @@
+import pygame
+
+
+def main():
+    pygame.init()
+    # Define screen size tuple
+    size = width, height = 1200, 900
+    screen = pygame.display.set_mode(size)
+
+
 if __name__ == "__main__":
-    pass
+    main()