the docstrings added at the begening and the end

constants.py

@@ -1,7 +1,10 @@
 """
 Simulation Constants
 """
-
+"""
+there is going to be 
+some changes
+"""
 
 class SimColor:
 """
@@ -69,3 +72,5 @@ class PreventativeMeasure:
         VACCINATE_POP,
         SHELTER_IN_PLACE
     ]
+
+"""this is the end.."""

constants.py~

@@ -0,0 +1,71 @@
+"""
+Simulation Constants
+"""
+
+
+class SimColor:
+"""
+Tuples corresponding to RGB colors
+"""
+    LIGHT_GREY = (240, 240, 240)
+    DARK_GREY = (30, 30, 50)
+    BLACK = (0, 0, 0)
+    LIMIT_LINE = (80, 80, 100)
+    INFECTED = (210, 100, 140)
+    RECOVERED = (0, 160, 0)
+    UNEXPOSED = (0, 120, 240)
+
+
+class Disease:
+"""
+Constants for disease
+"""
+    INFECTED = 0
+    RECOVERED = 1
+    UNEXPOSED = 2
+
+    DEFAULT_RECOVERY_PERIOD = 340
+
+    COLOR_MAP = {
+        INFECTED: SimColor.INFECTED,
+        RECOVERED: SimColor.RECOVERED,
+        UNEXPOSED: SimColor.UNEXPOSED
+    }
+
+
+class Screen:
+"""
+Constants for Screen
+"""
+    WIDTH = 680
+    HEIGHT = 480
+    FONT_SIZE = 18
+    GRAPH_X_UNIT = 0.8
+    MEDICAL_LIMIT = 50
+
+"""
+Class for initial condition of Patient
+"""
+class InitialCondition:
+    POP_UNEXPOSED = 49
+    POP_INFECTED = 1
+
+
+class HostConfig:
+    SIZE = 11
+    VACCINATION_DRIP = 3
+    PREVENTATIVE_MEASURE_ADHERENCE = 0.5
+    MAX_SPEED = 6
+    MIN_SPEED = 2
+
+
+class PreventativeMeasure:
+    SHELTER_IN_PLACE = 0
+    VACCINATE_POP = 1
+    LIMIT_TRAVEL = 2
+
+    SELECTED = [
+        LIMIT_TRAVEL,
+        VACCINATE_POP,
+        SHELTER_IN_PLACE
+    ]