Кальсина Яна. Переписывание контрольной работы. Б43

src/Walker/Walker_class.py

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+import random
+import math
+
+
+class Walker:
+    def __init__(self, events_and_prob):
+        if not events_and_prob:
+            raise ValueError("Переданный список пустой")
+        self.events_and_prob = events_and_prob
+        self.probability_check()
+        self.quantity_of_lines = len(self.events_and_prob)
+        self.overage_prob = 1 / self.quantity_of_lines
+
+        self.donors = []
+        self.recipients = []
+        self.table = [None] * self.quantity_of_lines
+
+        for i in range(len(self.events_and_prob)):
+            # список вида [...["событие", нужная вероятность, имеющаяся]...]
+            if self.events_and_prob[i][1] <= self.overage_prob:
+                self.events_and_prob[i].append(self.overage_prob)
+                self.donors.append(self.events_and_prob[i])
+            else:
+                self.events_and_prob[i].append(self.overage_prob)
+                self.recipients.append(self.events_and_prob[i])
+        self.build_table()
+
+    def probability_check(self):
+        i = 0
+        for el in self.events_and_prob:
+            i += el[1]
+        if i != 1:
+            raise ValueError("Вероятности в сумме не дают 1!")
+
+    def build_table(self):
+        i = 0
+        while self.donors and self.recipients:
+            donor = self.donors.pop()
+            recipient = self.recipients.pop()
+
+            donor_event, donor_needed_prob, donor_current_prob = donor
+            recipient_event, recipient_needed_prob, recipient_current_prob = recipient
+
+            donor_can_give = donor_current_prob - donor_needed_prob
+
+            recipient_current_prob += donor_can_give
+
+            recipient[2] = recipient_current_prob
+            if recipient_needed_prob >= recipient_current_prob:
+                self.recipients.append(recipient)
+            else:
+                self.donors.append(recipient)
+
+            barrier = self.overage_prob * i + (self.overage_prob - donor_can_give)
+
+            self.table[i] = [donor_event, recipient_event, barrier]
+            i += 1
+        self.table[-1] = [recipient_event, 0, 1]
+
+    def printall(self):
+        for i in range(len(self.table)):
+            print(self.table[i])
+
+    def get_random(self):
+        random_number = random.random()
+        line = math.floor(random_number * self.quantity_of_lines)
+        line = self.table[line]
+        rational_part = random_number - int(random_number)
+        if rational_part < line[2]:
+            return line[0]
+        return line[1]

tests/test_for_walker_class.py

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+from src.Walker.Walker_class import Walker
+import pytest
+
+
+def test_1_prob_occasion():
+    walker_scheme = Walker([["A", 1], ["D", 0]])
+    assert walker_scheme.get_random() == "A"
+
+
+def test_error():
+    with pytest.raises(ValueError, match="Вероятности в сумме не дают 1!"):
+        Walker([["A", 0], ["D", 0]])
+
+
+def test_empty_list():
+    with pytest.raises(ValueError, match="Переданный список пустой"):
+        Walker([])
+
+
+def test_error_sum_under_one():
+    with pytest.raises(ValueError, match="Вероятности в сумме не дают 1!"):
+        Walker([["A", 0.5], ["D", 0.4]])