return文は何をしますか？

Question

私は誕生日のパラドックス計算するプログラムを作成しようとしています：

import random 

def random_birthdays(): 
    count = 0 
    res = [] 
    for i in range(23): 
     res.append(random.randint(0, 365)) 
    res.sort() 
    return res 

def final(): 
    count = 0 
    i = 0 
    random_birthdays() 
    for day in res: 
     if res[i] == res[i + 1]: 
      count = count + 1 
      i = i + 1 
     else: 
      i = i + 1 
    return count 

def percentage(): 
    happens = 0 
    for i in range(100): 
     final() 
     happens = happens + count 
    percentage = happens/100 

percentage() 

しかし、私はこのエラーを取得しています：for day in res: res not definedを。

私はPythonの復帰部分を理解している方法が本当に間違っていると思います。私はそれを見て、resを返して、それを次の行の変数として使用する必要があるからです。

Answer 1

ようこそ！

returnには、返された値をobjectに格納する必要があります。

def final(): 
     count = 0 
     i = 0 
     res = random_birthdays() 
     for day in res: 
      if res[i] == res [i+1]: 
       count = count +1 
       i = i+1 
      else: 
       i = i+1 
     return count 

Answer 2

書き換えのビット：

from collections import Counter 
from math import factorial 
from random import randrange 

def duplicate_birthday(n): 
    """ 
    Given n people with random birthdays, 
     do any of them share a birthday? 
    """ 
    c = Counter(randrange(365) for _ in range(n)) 
    return max(c.values()) > 1 

def monte_carlo(n, tries = 1000): 
    return sum(1 for _ in range(tries) if duplicate_birthday(n))/tries 

def calculated_odds(n): 
    """ 
    Given n people with random birthdays, 
    calculate the odds that at least two share a birthday 
    """ 
    all_combos = 365 ** n 
    unique_combos = factorial(365)/factorial(365 - n) 
    return 1. - unique_combos/all_combos 

def main(): 
    print("Odds of N people sharing a birthday:") 
    for n in range(20, 26): 
     sim_pct = 100. * monte_carlo(n) 
     calc_pct = 100. * calculated_odds(n) 
     print("{:>2d}: {:>4.1f}% ({:>4.1f}%)".format(n, sim_pct, calc_pct)) 

if __name__ == "__main__": 
    main() 

与え

Odds of N people sharing a birthday: 
20: 42.5% (41.1%) 
21: 42.0% (44.4%) 
22: 48.8% (47.6%) 
23: 50.7% (50.7%) 
24: 52.2% (53.8%) 
25: 55.9% (56.9%)