3 of 4 All-in in the final round

Half In

This bot always bids half of what it has left, except in the final round where it will go all in.

class half_in:
  def __init__(self):
    self.money = 0
    self.round = -1
  def play_round(self, winner, win_amount):
    # Default actions:
    #  Collect 500 dollars
    self.money += 500
    #  If it was the winner: subtract the win_amount from his money
    if winner == 0:
      self.money -= win_amount
    # One round further
    self.round += 1

    # If it's the final round: bid all in
    if self.round == 10:
      return self.money
    # Else: Bid half what it has left:
    return self.money / 2

I never program in Python, so if you see any mistakes let me know..