wtf

quit_while_youre_ahead.py

#!/usr/bin/env python3
# Gambling Statistics Problem:
#     If you play roulette every day and quit whenever you're ahead by x amount, 
#     do you make money in the long run?
# Answer:
#     No.

import random

STARTING_BALANCE = 100000
BET_AMT = 100
MAX_EARNINGS = 100 * BET_AMT
MAX_LOSSES = 10 * BET_AMT
DAYS = 100000


def make_wager(winner=None, amt=None):
    return {
        'winner': winner or random.randint(0, 1),
        'amt': amt or 100,
    }

def toss_coin():
    return random.randint(0, 1)

def winnings(bet: dict, outcome: int):
    if outcome == bet['winner']:
        return bet['amt']
    else:
        return -1 * bet['amt']


def trade(starting_balance: int=STARTING_BALANCE, max_earnings: int=MAX_EARNINGS, max_losses: int=MAX_LOSSES, bet_amt: int=BET_AMT):
    """trade using a quit-while-you're ahead strategy"""
    # print(f'Starting with {t.balance}')
    balance = starting_balance
    while (balance < (starting_balance + max_earnings)
           and balance > (starting_balance - max_losses)):

        bet = make_wager()
        outcome = toss_coin()
        delta = winnings(bet, outcome)
        # print(f'{["lost", "won "][outcome == bet["winner"]]} {balance} + {delta}')
        balance += delta

    return balance


if __name__ == '__main__':
    days = DAYS

    days_won, days_lost = 0, 0
    total_input, total_output = 0, 0

    for day in range(days):
        total_input += STARTING_BALANCE
        end_of_day_outcome = trade(STARTING_BALANCE, max_earnings=MAX_EARNINGS, max_losses=MAX_LOSSES, bet_amt=BET_AMT)

        if end_of_day_outcome <= STARTING_BALANCE + MAX_LOSSES:
            days_won += 1
        else:
            days_lost += 1

        total_output += end_of_day_outcome

        # if total_output - total_input < (0 - MAX_LOSSES):
            # break

    print(f'Days where you came out ahead:  {days_won}')
    print(f'Days where you came out behind: {days_lost}')
    print(f'Total amount bet:               {total_input}')
    print(f'Total amount remaining:         {total_output}')
    print(f'Net winnings:                   {total_output - total_input}')

Breaks at line 23: def winnings(bet: dict, outcome: int):

@robbrulinski if you're using python 2.7 change the following lines:
line 23: def winnings(bet= dict, outcome= int):
line 30: def trade(starting_balance= int(STARTING_BALANCE), max_earnings= int(MAX_EARNINGS), max_losses= int(MAX_LOSSES), bet_amt= int(BET_AMT)):
lines 66-70:
print('won: {}'.format(days_won))
print('lost: {}'.format(days_lost))
print('total in: {}'.format(total_input))
print('total out: {}'.format(total_output))
print('net: {}'.format(total_output - total_input))