simulate-red-packets.py

import random
import pandas as pd

def simulate(n):
  trial_results = []
  while True:
    if len(trial_results) == n:
      return trial_results
    else:
      cards = []
      while True:
        cards.append(random.choice(['H','S','W']))

        # if I have at least 4 cards, check whether I have ['H','H','S','W']
        if(len(cards)>=4 and
           "S" in cards and 
           "W" in cards and 
           cards.count("H")>1 ):

             # record the result (number of cards it took to win)
             trial_results.append(len(cards))
             break

trial_results = simulate(10000)

df = pd.DataFrame(trial_results, columns=['trial_results'])

pd.set_option("display.max_rows", 10)
print(df)
print("mean from 10000 trials:")
print(df['trial_results'].mean())