From 9830f6b04be9d97ea46074f26de960645c0ed975 Mon Sep 17 00:00:00 2001
From: cheeks <134818917+leftovertoast@users.noreply.github.com>
Date: Thu, 13 Mar 2025 21:41:32 +0000
Subject: [PATCH] completed birthdayparadox.py

---
 birthdayparadox.py | 44 +++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 43 insertions(+), 1 deletion(-)

diff --git a/birthdayparadox.py b/birthdayparadox.py
index 2a06ece..2fc8d17 100644
--- a/birthdayparadox.py
+++ b/birthdayparadox.py
@@ -21,6 +21,7 @@ def getBirthdays(numberOfBirthdays):
         birthdays.append(birthday)
     return birthdays
 
+
 def getMatch(birthdays):
     """Returns the date object of a birthday that occurs more than once
     in the birthdays list."""
@@ -33,8 +34,10 @@ def getMatch(birthdays):
             if birthdayA == birthdayB:
                 return birthdayA # Return the matching birthday
 
+
 # Display the intro:
 print('''Birthday Paradox, by Al Sweigart al@inventwithpython.com
+
 The Birthday Paradox shows us that in a group of N people, the odds
 that two of them have matching birthdays is surprisingly large.
 This program does a Monte Carlo simulation (that is, repeated random
@@ -42,6 +45,7 @@ simulations) to explore this concept.
 
 (It's not actually a paradox, it's just a surprising result.)
 ''')
+
 # Set up a tuple of month names in order:
 MONTHS = ('Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 
         'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec')
@@ -62,8 +66,46 @@ for i, birthday in enumerate(birthdays):
         # Display a comma for each birthday after the first birthday. 
         print(', ', end='')
     monthName = MONTHS[birthday.month - 1]
-    dateText = '{} {}'.format(monthName, match.day)
+    dateText = '{} {}'.format(monthName, birthday.day)
     print(dateText, end='')
 print()
 print()
 
+# Determine if there are two birthdays that match. 
+match = getMatch(birthdays)
+
+# Display the results:
+print('In this simulation, ', end='')
+if match != None:
+    monthName = MONTHS[match.month - 1]
+    dateText = '{} {}'.format(monthName, match.day)
+    print('multiple people have a birthday on', dateText)
+else:
+    print('there are no matching birthdays.')
+print()
+
+# Run through 100,000 simulations:
+print('Generating', numBDays, 'random birthdays 100,000 times...')
+input('Press Enter to begin...')
+
+print('Let\'s run another 100,000 simulations.')
+simMatch = 0 # How many simulations had matching birthdays in them. 
+for i in range(100_000):
+    # Report on the progress every 10,000 simulations:
+    if i % 1000 == 0:
+        print(i, 'simulations run...')
+    birthdays = getBirthdays(numBDays)
+    if getMatch(birthdays) != None:
+        simMatch = simMatch + 1
+print('100,000 simulations run.')
+
+# Display simulation results:
+probability = round(simMatch / 100_000 * 100, 2)
+print('Out of 100,000 simulations of', numBDays, 'people, there was a a')
+print('matching birthday in that group', simMatch, 'times. This means')
+print('that', numBDays, 'people have a', probability, '% chance of')
+print('having a matching birthday in their group.')
+print('That\'s probably more than you would think!')
+
+
+#if __name__ == '__main__':