Добавил определение случайного ивента и стабилизацию везения.

Почистил код.
Удалил лишнее.

modules/DB.py

@@ -5,7 +5,7 @@ class UseDB:
     def __init__(self, collection_name):
         self.series_collection = None
         self.client = MongoClient('localhost', 27017)
-        self.db = self.client['stepik']
+        self.db = self.client['toads']
         self.series_collection = self.db[collection_name]
 
     def find_document(self, elements):

modules/GameMenu.py

@@ -4,10 +4,10 @@ from pygame import *
 
 def menu():
     init()
-    DISPLAYSURF = display.set_mode((480, 600))
+    DISPLAYPORT = display.set_mode((480, 600))
     display.set_caption('The Lonely Shooter')
     background = image.load('styles/background.jpeg').convert()
-    DISPLAYSURF.blit(background, background.get_rect())
+    DISPLAYPORT.blit(background, background.get_rect())
     display.update()
     while True:
         events = event.poll()

modules/Mathematics.py

@@ -0,0 +1,53 @@
+from modules.DB import UseDB
+from loguru import logger
+import random
+
+
+def get_random_event():
+    db = UseDB("events")
+    response = db.find_document({})
+    random_event = random.choices([i["_id"] for i in response], weights=[i["probability"] for i in response])
+    return db.find_document({"_id": random_event[0]})[0]
+
+
+def recalculation_events(well):
+    if well:
+        db = UseDB("events")
+        not_well_events = db.find_document({"well": False})
+        for i in not_well_events:
+            db.update_document({"_id": i["_id"]}, {"probability": i["probability"] + 5})
+        well_events = db.find_document({"well": True})
+        cooficent = len(not_well_events) * 5 / len(well_events)
+        for i in well_events:
+            db.update_document({"_id": i["_id"]}, {"probability": i["probability"] - cooficent})
+    else:
+        db = UseDB("events")
+        well_events = db.find_document({"well": True})
+        for i in well_events:
+            db.update_document({"_id": i["_id"]}, {"probability": i["probability"] + 5})
+        not_well_events = db.find_document({"well": False})
+        cooficent = len(well_events) * 5 / len(not_well_events)
+        for i in not_well_events:
+            db.update_document({"_id": i["_id"]}, {"probability": i["probability"] - cooficent})
+
+
+def start_calculating():
+    logger.remove()
+    logger.add("conf/log.log", level="INFO")
+    logger.info("Валидация началась")
+    db = UseDB("events")
+    response = db.find_document({})
+    sum_percent_probability = sum([i["probability"] for i in response])
+    sum_percent_probability_in_events = sum([sum(i["probability_consequence"]) for i in response])
+    if sum_percent_probability != 100:
+        logger.critical("Сумма вероятностей всех ивентов не равна 100, это плохо, не надо так")
+        quit(0)
+    if sum_percent_probability_in_events != len(response) * 100:
+        logger.critical("Проблема в каком-то ивенте, сумма вероятностей не правильная")
+        quit(0)
+    for i in response:
+        if not (len(i["variants"]) == len(i["consequence"]) == len(i["probability_consequence"])):
+            logger.critical(f"Ошибка в ивенте {i['name']}. Разница в длинах variants, consequence "
+                            f"и probability_consequence")
+            quit(0)
+    logger.info("Валидация игры успешно прошла")