Due at 11:59:59 pm on Thursday, 11/26/2019.

Starter Files

Download lab10.zip. Inside the archive, you will find starter files for the questions in this lab, along with a copy of the OK autograder.

Submission

By the end of this lab, you should have submitted the lab with `python3 ok --submit`. You may submit more than once before the deadline; only the final submission will be graded. Check that you have successfully submitted your code on okpy.org. See this article for more instructions on okpy and submitting assignments.

• Submit the `lab10.py` file to `ok`.

Inheritance

Let's implement a game called Election. In this game, two players compete to try and earn the most votes. Both players start with 0 votes and 100 popularity.

The two players alternate turns, and the first player starts. Each turn, the current player chooses an action. There are two types of actions:

• The player can debate, and either gain or lose 50 popularity. If the player has popularity `p1` and the other player has popularity `p2`, then the probability that the player gains 50 popularity is `max(0.1, p1 / (p1 + p2))` Note that the `max` causes the probability to never be lower than 0.1.
• The player can give a speech. If the player has popularity `p1` and the other player has popularity `p2`, then the player gains `p1 // 10` votes and popularity and the other player loses `p2 // 10` popularity.

The game ends when a player reaches 50 votes, or after a total of 10 turns have been played (each player has taken 5 turns). Whoever has more votes at the end of the game is the winner!

Question 1: Player

First, let's implement the `Player` class. Fill in the `debate` and `speech` methods, that take in another `Player` `other`, and implement the correct behavior as detailed above. Here are two additional things to keep in mind:

• In the `debate` method, you should call the provided `random` function, which returns a random float between 0 and 1. The player should gain 50 popularity if the random number is smaller than the probability described above, and lose 50 popularity otherwise.
• Neither players' votes or popularity should ever become negative. If this happens, set it equal to 0 instead.
• This problem has additional hidden doc tests that will test full correctness.
``````### Phase 1: The Player Class
class Player:
"""
>>> random = make_test_random()
>>> p1 = Player('Hill')
>>> p2 = Player('Don')
>>> p1.popularity
100
>>> p1.debate(p2)  # random() should return 0.0
>>> p1.popularity
150
>>> p2.popularity
100
>>> p2.votes
0
>>> p2.speech(p1)
>>> p2.votes
10
>>> p2.popularity
110
>>> p1.popularity
135

>>> # Additional correctness tests
>>> p1.speech(p2)
>>> p1.votes
13
>>> p1.popularity
148
>>> p2.votes
10
>>> p2.popularity
99
>>> for _ in range(4):  # 0.1, 0.2, 0.3, 0.4
...     p1.debate(p2)
>>> p2.debate(p1)
>>> p2.popularity
49
>>> p2.debate(p1)
>>> p2.popularity
0
"""
def __init__(self, name):
self.name = name
self.votes = 0
self.popularity = 100

def debate(self, other):
"*** YOUR CODE HERE ***"
prob = max(0.1, self.popularity / (self.popularity + other.popularity))
if random() < prob:
self.popularity += 50
else:
self.popularity = max(0, self.popularity - 50)
def speech(self, other):
"*** YOUR CODE HERE ***"
self.votes += self.popularity // 10
self.popularity += self.popularity // 10
other.popularity -= other.popularity // 10
def choose(self, other):
return self.speech``````

Use OK to test your code:

``python3 ok -q Player``

Question 2: Game

Now, implement the `Game` class. Fill in the `play` method, which should alternate between the two players, starting with `p1`, and have each player take one turn at a time. The `choose` method in the `Player` class returns the method, either `debate` or `speech`, that should be called to perform the action.

In addition, fill in the `winner` property method, which should return the player with more votes, or `None` if the players are tied. This problem has additional hidden doc tests that will test full correctness.

``````### Phase 2: The Game Class
class Game:
"""
>>> p1, p2 = Player('Hill'), Player('Don')
>>> g = Game(p1, p2)
>>> winner = g.play()
>>> p1 is winner
True

>>> # Additional correctness tests
>>> winner is g.winner
True
>>> g.turn
10
>>> p1.votes = p2.votes
>>> print(g.winner)
None
"""
def __init__(self, player1, player2):
self.p1 = player1
self.p2 = player2
self.turn = 0

def play(self):
while not self.game_over:
"*** YOUR CODE HERE ***"
if self.turn % 2 == 0:
curr, other = self.p1, self.p2
else:
curr, other = self.p2, self.p1
curr.choose(other)(other)
self.turn += 1        return self.winner

@property
def game_over(self):
return max(self.p1.votes, self.p2.votes) >= 50 or self.turn >= 10

@property
def winner(self):
"*** YOUR CODE HERE ***"
if self.p1.votes > self.p2.votes:
return self.p1
elif self.p2.votes > self.p1.votes:
return self.p2
else:
return None``````

Use OK to test your code:

``python3 ok -q Game``

Question 3: New Players

The `choose` method in the `Player` class is boring, because it always returns the `speech` method. Let's implement two new classes that inherit from `Player`, but have more interesting `choose` methods.

Implement the `choose` method in the `AggressivePlayer` class, which returns the `debate` method if the player's popularity is less than or equal to `other`'s popularity, and `speech` otherwise. Also implement the `choose` method in the `CautiousPlayer` class, which returns the `debate` method if the player's popularity is 0, and `speech` otherwise. This problem has additional hidden doc tests that will test full correctness.

``````### Phase 3: New Players
class AggressivePlayer(Player):
"""
>>> random = make_test_random()
>>> p1, p2 = AggressivePlayer('Don'), Player('Hill')
>>> g = Game(p1, p2)
>>> winner = g.play()
>>> p1 is winner
True

>>> # Additional correctness tests
>>> p1.popularity = p2.popularity
>>> p1.choose(p2) == p1.debate
True
>>> p1.popularity += 1
>>> p1.choose(p2) == p1.debate
False
>>> p2.choose(p1) == p2.speech
True
"""
def choose(self, other):
"*** YOUR CODE HERE ***"
if self.popularity <= other.popularity:
return self.debate
else:
return self.speech
class CautiousPlayer(Player):
"""
>>> random = make_test_random()
>>> p1, p2 = CautiousPlayer('Hill'), AggressivePlayer('Don')
>>> p1.popularity = 0
>>> p1.choose(p2) == p1.debate
True
>>> p1.popularity = 1
>>> p1.choose(p2) == p1.debate
False

>>> # Additional correctness tests
>>> p2.choose(p1) == p2.speech
True
"""
def choose(self, other):
"*** YOUR CODE HERE ***"
if self.popularity == 0:
return self.debate
else:
return self.speech``````

Use OK to test your code:

``````python3 ok -q AggressivePlayer
python3 ok -q CautiousPlayer``````

Question 4: Quidditch

It's time for the opening quidditch match of the season! We represent the various positions for players with the `QuidditchPlayer` class and its subclasses. Every player begins with a `base_energy` level, but every position requires a different proportion of energy. Fill in the `energy` method for the `Beater`, `Chaser`, `Seeker`, and `Keeper` classes, according to their docstrings. In addition, fill in the `__init__` method for the `Chaser` class.

``````class Player:
def __init__(self, name, base_energy):
"""
Players have a name, and begin with base_energy.
"""
self.name = name
self.base_energy = base_energy

def energy(self):
return self.base_energy``````
``````class Beater(QuidditchPlayer):
role = "bludgers"

def energy(self, time):
"""
Returns the amount of energy left after playing for time minutes.
After playing for time minutes, Beaters lose their base energy level
divided by the number of minutes. If time is 0, catch the ZeroDivisionError
and print "You can't divide by zero!" instead.
>>> fred = Beater("Fred Weasley", 640)
>>> fred.energy(40)
624.0
>>> fred.energy(0)
You can't divide by zero!
"""
"*** YOUR CODE HERE ***"

try:
return self.base_energy - (self.base_energy / time)
except ZeroDivisionError as e:
print("You can't divide by zero!")``````

Use OK to test your code:

``python3 ok -q Beater.energy``
``````class Chaser(QuidditchPlayer):
role = "score"
energy_expended = 20

def __init__(self, name, base_energy, goals):
"""
Chasers have a name, score goals, and begin with base_energy.
"""
"*** YOUR CODE HERE ***"

self.name = name
self.base_energy = base_energy
self.goals = goals
def energy(self, time):
"""
Returns the amount of energy left after playing for time minutes. For every goal
they score, they use energy_expended units of energy. In addition, they also use
10% of energy_expended if the number of minutes they have played is a multiple of 9.
>>> katie = Chaser("Katie Bell", 230, 2)
>>> katie.energy(20)
190
>>> ginny = Chaser("Ginny Weasley", 400, 3)
>>> ginny.energy(45)
338.0
"""
"*** YOUR CODE HERE ***"

energy = self.base_energy
if time % 9 == 0:
energy = energy - (0.1 * Chaser.energy_expended)
energy = energy - (self.goals * Chaser.energy_expended)
else:
energy = energy - (self.goals * Chaser.energy_expended)
return energy``````

Use OK to test your code:

``python3 ok -q Chaser.energy``
``````class Seeker(QuidditchPlayer):
role = "snitch"
energy_expended = 5

def energy(self, time):
"""
Returns the amount of energy after time minutes. Seekers expend energy_expended
units of their energy for every minute they have been playing.
>>> harry = Seeker("Harry Potter", 700)
>>> harry.energy(30)
550
"""
"*** YOUR CODE HERE ***"

return self.base_energy - (time * Seeker.energy_expended)``````

Use OK to test your code:

``python3 ok -q Seeker.energy``
``````class Keeper(QuidditchPlayer):
role = "guard"
energy_expended = 50

def energy(self, time):
"""
Returns the amount of energy after time minutes. If less than 30 minutes have
passed, then Keepers do not lose any energy. If 30 minutes or more have passed,
then Keepers expend 80% of their energy_expended units for every full 15
minutes that pass.
>>> oliver = Keeper("Oliver Wood", 380)
>>> oliver.energy(45)
260.0
"""
"*** YOUR CODE HERE ***"

energy = self.base_energy
if time < 30:
return self.base_energy
else:
for i in range(time // 15):
energy = energy - (0.8 * Keeper.energy_expended)
return energy``````

Use OK to test your code:

``python3 ok -q Keeper.energy``

After you finish implementing the QuidditchPlayers, run the following command in your terminal to play the game:

``python3 -i quidditch_game.py``

Preparing for Project 2: Debugging

Question 5: Werewolf

Now, you want to play a game, inspired by Werewolf, with a group of your friends. A `Pl88yer` can either be a `Werewolf`, or a `Villager`. In this game, you can have 4 or more players. The first 2 players are automatically designated to be Werewolves, while everyone else is assigned to be a Villager. One play of the game involves all of the players voting for a player who they believe to be a Werewolf; in this implementation, all players, except yourself, arbitrarily vote for themselves. At the end of each play, the player with the most votes is removed from the game. Each play of the game alternates between daytime and nighttime. If it is nighttime, only votes by werewolves count.

The game ends when there are no werewolves left, which means the villagers won, or when there are more werewolves than villagers, which means the werewolves have won.

However, there are bugs in the code for the game! Read through the code and fix all of the bugs so that the game can work properly. As hint, there are at least four bugs in the code! For this lab there is a hidden test. In other words, we will be running a test against your code that you don't have access to, so make sure to be thorough! You should not need to add any lines - only edit existing lines.

``````def get_most_common_element(lst):
return max(set(lst), key=lst.count)

class Pl88yer:
def __init__(self, name):
self.name = name
self.active = True

class Werewolf(Pl88yer):
def __init__(self, name):
Pl88yer.__init__(self, name)

def reveal_player_type(self):
print("You are a werewolf!")

class Villager(Pl88yer):
def __init__(self, name):
Villager.__init__(self, name)

def reveal_player_type(self):
print("You are a villager!")

class WerewolfGame:
def __init__(self, players, your_name):
"""
Sets the game up. players is a list of strings that are names of all
of the players. your_name is a string and must be one of the players.
>>> game = WerewolfGame(["a", "b", "c", "d", "e", "f"], "a")
You are a werewolf!
>>> game.your_name
'a'
>>> game.play("b")
'Keep playing!'
>>> len(game.werewolves)
1
>>> len(game.villagers)
4
>>> game.play("c")
'Keep playing!'
>>> game.play("d")
'Keep playing!'
>>> game.play("a")
'Villagers win!'
>>> game.werewolves
[]
>>> len(game.villagers)
2
"""
if len(players) < 4:
raise Exception("Not enough players!")
names = players[0:2]
self.your_name = your_name
self.werewolves = [Werewolf(self, w) for w in names]
self.villagers = [Villager(self, p) for p in players if p not in names]
self.name_to_player = {}

for werewolf in self.werewolves:
self.name_to_player[werewolf.name] = werewolf

for villager in self.villagers:
self.name_to_player[villager.name] = villager

player = self.name_to_player[your_name]
player.reveal_player_type()

self.state = "night"

def play(self, vote):
"""
While the game is still being played, make a move. vote is the player
who you vote for, because you believe they are on the opposing team.
You can continue playing until either the villagers or the werewolves win.
"""
self.make_move(vote)
if not self.check_if_end_of_game():
return "Keep playing!"
else:
if len(self.werewolves) == 0:
return "Villagers win!"
elif len(self.werewolves) > len(self.villagers):
return "Werewolves win!"

def make_move(self, vote):
"""
Every player votes (players arbitrarily vote for themselves). Then,
if the state of the game is day, remove the player with the most votes
overall, and set the state to night. If the state of the game is night,
remove the player with the most votes by werewolves, and set the state to day.
"""
votes = []
werewolf_votes = []

if self.state == "night":
werewolf_votes.append(vote)
votes.append(vote)

for player in self.name_to_player:
if self.state == "night" and isinstance(player, Werewolf(name)):
werewolf_votes.append(player)
votes.append(player)

if self.state == "day":
majority_vote = get_most_common_element(votes)
self.state = "night"
elif self.state == "night":
majority_vote = get_most_common_element(werewolf_votes)
self.state = "day"

if majority_vote in self.name_to_player:
self.remove_player(majority_vote)
else:
raise Exception("Invalid player.")

def remove_player(player_to_remove):
"""
Set the player with the majority vote to inactive, and remove it from
its respective list of players.
"""
player = self.name_to_player[player_to_remove]
self.active = False

if player in self.werewolves:
self.werewolves.remove(player)
elif player in self.villagers:
self.villagers.remove(player)
else:
print("Player already removed!")

def check_if_end_of_game(self):
"""
Returns True if the game is over, and False if it is not. The game is over when
there are no werewolves remaining, or if there are more werewolves than villagers.
"""

if len(WerewolfGame.werewolves) == 0:
return True
elif len(WerewolfGame.werewolves) > len(WerewolfGame.villagers):
return True
else:
return False``````

Run the following command in your terminal to play around with your code:

``python3 -i lab10.py``

After running the above command, enter the below line to actually start a game and play through the code that you've debugged. We highly recommend you do this a couple times to test your code and make sure it's bug free. If you need a refresher on the commands for interacting with the game, refer to the doctests for this question!

``game = WerewolfGame(["a", "b", "c", "d", "e", "f"], "a")``
``````def get_most_common_element(lst):
return max(set(lst), key=lst.count)

class Pl88yer:
def __init__(self, name):
self.name = name
self.active = True

class Werewolf(Pl88yer):
def __init__(self, name):
Pl88yer.__init__(self, name)

def reveal_player_type(self):
print("You are a werewolf!")

class Villager(Pl88yer):
def __init__(self, name):
Villager.__init__(self, name)

def reveal_player_type(self):
print("You are a villager!")

class WerewolfGame:
def __init__(self, players, your_name):
"""
Sets the game up. players is a list of strings that are names of all
of the players. your_name is a string and must be one of the players.
>>> game = WerewolfGame(["a", "b", "c", "d", "e", "f"], "a")
You are a werewolf!
>>> game.your_name
'a'
>>> game.play("b")
'Keep playing!'
>>> len(game.werewolves)
1
>>> len(game.villagers)
4
>>> game.play("c")
'Keep playing!'
>>> game.play("d")
'Keep playing!'
>>> game.play("a")
'Villagers win!'
>>> game.werewolves
[]
>>> len(game.villagers)
2
"""
if len(players) < 4:
raise Exception("Not enough players!")
names = players[0:2]
self.your_name = your_name
self.werewolves = [Werewolf(self, w) for w in names]
self.villagers = [Villager(self, p) for p in players if p not in names]
self.name_to_player = {}

for werewolf in self.werewolves:
self.name_to_player[werewolf.name] = werewolf

for villager in self.villagers:
self.name_to_player[villager.name] = villager

player = self.name_to_player[your_name]
player.reveal_player_type()

self.state = "night"

def play(self, vote):
"""
While the game is still being played, make a move. vote is the player
who you vote for, because you believe they are on the opposing team.
You can continue playing until either the villagers or the werewolves win.
"""
self.make_move(vote)
if not self.check_if_end_of_game():
return "Keep playing!"
else:
if len(self.werewolves) == 0:
return "Villagers win!"
elif len(self.werewolves) > len(self.villagers):
return "Werewolves win!"

def make_move(self, vote):
"""
Every player votes (players arbitrarily vote for themselves). Then,
if the state of the game is day, remove the player with the most votes
overall, and set the state to night. If the state of the game is night,
remove the player with the most votes by werewolves, and set the state to day.
"""
votes = []
werewolf_votes = []

if self.state == "night":
werewolf_votes.append(vote)
votes.append(vote)

for player in self.name_to_player:
if self.state == "night" and isinstance(player, Werewolf(name)):
werewolf_votes.append(player)
votes.append(player)

if self.state == "day":
majority_vote = get_most_common_element(votes)
self.state = "night"
elif self.state == "night":
majority_vote = get_most_common_element(werewolf_votes)
self.state = "day"

if majority_vote in self.name_to_player:
self.remove_player(majority_vote)
else:
raise Exception("Invalid player.")

def remove_player(player_to_remove):
"""
Set the player with the majority vote to inactive, and remove it from
its respective list of players.
"""
player = self.name_to_player[player_to_remove]
self.active = False

if player in self.werewolves:
self.werewolves.remove(player)
elif player in self.villagers:
self.villagers.remove(player)
else:
print("Player already removed!")

def check_if_end_of_game(self):
"""
Returns True if the game is over, and False if it is not. The game is over when
there are no werewolves remaining, or if there are more werewolves than villagers.
"""

if len(WerewolfGame.werewolves) == 0:
return True
elif len(WerewolfGame.werewolves) > len(WerewolfGame.villagers):
return True
else:
return False``````

There are no OK tests for this question! However, it will still be graded as part of the lab, so be sure that your solution works before submitting!