辅导 program、讲解 Python程序语言
Welcome to A1.1 - Pokemon!
Welcome to the wonderful world of Pokemon. Pokemon Battles is a game played
between teams of opposing pokemon in an attempt to see who is the very best, like no
one ever was! Pokemon have stats like attack and defense, can evolve into other
monsters, and level up.
In this assignment you'll be working on many of the features of the Pokemon Battles
game, which should also test you on your ability to apply the concepts covered in the
first 4 weeks of Fundamentals of Algorithms.
But, this is too easy! To make sure you are demonstrating all of the topics covered in
this unit, the following restrictions are in place.
• Any use of python inbuilt lists, dictionaries, sets, etc. Is banned. Use of such
structures nulls both the test case and approach marks for the affected
task. You can however use fixed size tuples. (Please also read the FAQ
announcement in the Forum.)
• Accessing the internals of the data_structures classes outside of the definition of
the class is strictly prohibited (You can't access .array of CircularQueue for
example, only interact with its methods)
• Not only does your code need to be functional, it needs to be the most efficient
choice that is best suited for the problem. In general, if there is a choice that is
efficient and requires less code, not choosing this will lose you marks (So don't
use an array when a queue would also work).
With all that in mind, make sure to read the next slide for a bunch of small tid-bits and
we hope you enjoy this assignment!
Basic Introduction to Pokemon Battles
Basic Premise
Pokemon
The titular Pokemon are the backbone of the Pokemon Battles. There are different
types of pokemon each with their own names and stats, and one type of pokemon can
evolve into another type of pokemon when they level up.
Pokemon have the following information:
• Health
• Level
• Defence
• Type
• Battle Power (attack points)
• Name
• Evolution Line
• Experience
• Speed
These stats will be covered over the future tasks but here is a short overview of each of
them:
1. Health - This is the stat that lets you know how many health points a Pokemon has
before it faints. Once the Pokemon gets attacked, it loses some health and once the
health drops to 0, the Pokemon faints
2. Level - This stat refers to the level that the Pokemon is on. Once a Pokemon battles
another and makes it faint, the level of the Pokemon goes up by 1, boosting most of its
other stats.
3. Defence - This stat refers to the resistance that is offered by the Pokemon when it
gets attacked. You will learn more about the use of this stat when we discuss battling.
4. Type - A Pokemon's type affects the amount of damage it can do to another
Pokemon. You will learn more about this in Task 1.
5. Battle Power - This stat refers to the amount of base damage a Pokemon does to
another during the course of a battle.
6. Name - This refers to the name of the Pokemon
7. Evolution Line - This is a list of the Evolution names for this line of Pokemon. The
length of this list can vary as many Pokemon don't evolve, evolve once or even twice in
some cases!
8. Experience - This stat refers to the experience that a Pokemon has. A pokemon gains
experience from battling another pokemon.
9. Speed - This stat refers to the speed of the Pokemon. Speed determines how fast the
Pokemon is and the faster Pokemon attacks first.
What is PokemonBase?
Because there are over 70 Pokemon to define, and we don't want to write out all the
classes individually. In particular, because almost all of the logic for all Pokemon are the
same, all we have to do is define this shared logic in PokemonBase. Then Pokemon.py
creates different classes, which all inherit from PokemonBase, and implements all of the
abstract class methods at the bottom of pokemon_base.py.
For example, you can do the following without touching the assignment and it works
just fine:
Run
PYTHON
1
2
3
4
5
6
7
8
from pokemon import Charmander, Gastly
charmander = Charmander()
gastly = Gastly()
print(charmander.get_name()) # Charmander
print(charmander.get_poketype()) # PokeType.FIRE
print(gastly.get_evolution()) # ['Gastly', 'Haunter', 'Gengar
']
Teams
Pokemon are combined to form teams, which are used in battle. There are multiple
options for teams, such as the team mode, and selection mode, but these will be
covered in more detail in task 3.
Battling
Battling is done between two teams in a turn-based manner, where every "turn"
includes an action from both teams. In a battle, each team selects one Pokemon to be
currently out on the field, while the rest of each team waits to help out.
Battle anatomy
In a battle, turns continue to occur until one or both teams have no more pokemon left
(in the team and on the field). If a pokemon on the field is killed (HP <= 0), then a new
pokemon from the team is sent out at the end of the turn.
Turn anatomy
In a Battle turn, each team selects an action, either ATTACK or SPECIAL. If SPECIAL is
chosen, the pokemon is returned to the team, the method .special() is called on the
team object, and a pokemon is retrieved from the team (possibly the same pokemon).
If ATTACK is chosen, then the currently out-on-the-field pokemon attacks the currently
out-on-the-field pokemon for the other team.
Two things to note:
1. SPECIAL actions are always completed before ATTACK actions
2. If both teams ATTACK, then some special logic occurs:
The pokemon with the higher speed stat attacks first. If the slower pokemon is still alive
after this (HP > 0), then it can attack in retaliation. If the speed stat of both pokemon is
equal, then both pokemon attack simultaneously, ignoring whether the attack they are
receiving would kill them.
The process of pokemon attacking pokemon is defined as follows:
Step 1: Compute the damage
This is done by comparing pokemon1's attack (call it attack) and pokemon2's defense
(call it defense).
• If defense < attack / 2: damage = attack - defense
• Otherwise, If defence < attack: damage = ceil(attack * 5/8 - defense / 4)
• Otherwise, damage = ceil(attack / 4)
Step 2: Apply multipliers
When two Pokemon attack, the element of each Pokemon is considered. For example,
Squirtle is a Water Elemental Pokemon, where as Charmander is a Fire Elemental
Pokemon. Since Water has an effectiveness coefficient of 2 against Fire, this is used to
multiply by the calculated damage:
effective_damage = damage * 2
Then, you apply the trainer's Pokedex completion multiplier, which can be obtained as
a ratio between the attacking trainer's Pokedex completion vs the defending trainer's
Pokedex completion. This is discussed in detail (and will make more sense once you
read) Task 3 and the Battle Logic slide
effective_damage = effective_damage *
(attacking_pokedex_completion/defending_pokedex_completion)
Step 3: Get the ceiling of the effective_damage
Since at this point the damage may have a decimal component, round this number up.
Step 4: Deduct HP from pokemon2 equal to the effective_damage.
Note: During defense pokemon2 might reduce the effective_damage by half.
Leveling up
If at the end of a turn, one Pokemon is alive and the other is not, then the alive
Pokemon levels up. This may change the Pokemon's stats, and if they have an
evolution, will force the Pokemon to evolve.
When leveling up the difference between a Pokemon's max hp and current hp must be
maintained.
Evolution
Some Pokemon types can evolve into other Pokemon types. The PokemonBase method
get_evolution will tell you whether this Pokemon type can evolve. If the pokemon
cannot evolve, the returned list only contains the Pokemon itself. Otherwise, the
returned value is a list of its evolution names. For example
Charmander.get_evolution() == ['Charmeleon', 'Charizard'].
However, for a Pokemon (object) to evolve in battle, the following must be true:
• The Pokemon type must be able to evolve (get_evolution is returns just the
current Pokemon's name instead. i.e. - it doesn't have an evolution)
• The Pokemon must be a different level from the one it originally started as
To evolve a Pokemon, the evolve method is called. The evolve method modifies the
current object, changing its stats and upgrading the Pokemon to its new evolution.
Battle Tower
The Battle Tower is a battle feature where one team faces a gauntlet of other teams in
succession, and is covered in more detail in Task 4.
[TASK1] Element Effectiveness +
Pokemon Base
We are going to set up the Element effectiveness in this task. All your work will be in the
pokemon_base.py file.
For starters, you have been given a file called type_effectiveness.csv which contains a
table defining the type effectiveness for each type against each other.
Your job in this task is to:
• populate the EFFECT_TABLE in the TypeEffectiveness class. Some of the code
has already been done for you so you need to complete the rest.
• complete the method get_effectiveness which returns a float based on the
attacking and defending types supplied as arguments to the method.
Make sure to set up the table correctly. One example is that get_effectiveness(PokeType.WATER,
PokeType.GRASS) should return 0.5
Additionally, have a look at the PokemonBase class. Most of these methods have already
been done for you, however, you will need to implement the following:
• _evolve: This method will evolve the Pokemon. You don't need to check if the
pokemon needs to evolve as this is done in the level_up method. However,
what you need to do is to:
o change the name of the pokemon to the next in the evolution line
o set the battle power, health, speed and defence to 1.5 times what it
currently is set to
• attack: This method will return the attack points when this Pokemon is battling.
This method should return the product of the Pokemon's current battle_power
and the type effectiveness of the Pokemon vs the type of the defending
Pokemon
Think carefully about the data structure that you are going to use in this task!
[TASK 2] Poke Team
A reminder that use of inbuilt lists, dictionaries, sets are banned, and using less suited data structures
will result in loss of marks.
For methods that differ in complexity based on the team mode selected, please include separate
complexity analysis for all 3 team modes (For example, O(1) best/worst for FRONT, O(1) best/worst for
BACK, O(n^5log(n!)) for OPTIMISE)
Now that we have Pokemon and can create them and view stats, it's time to group
them into a team, in preparation for our battles!
You will be working on the file poke_team.py
Teams are a bit complicated, and have a few different creation options, so we'll go
through all the details here.
What is a Team?
A team is an ordered collection of Pokemon, with an upper limit on the total number of
monsters contained (this is currently set at 6, but you should design your code so that
this limit is easily adjustable)
Team should have the following instance variable, although you can have more:
• self.team to store the team that the trainer has
Teams have the following methods:
• __init__ , to initialise the team. This SHOULD NOT take any additional
arguments. However, if you are adding some arguments, you should provide
default values for them so they don't fail the tests.
• choose_manually, to let the user choose upto 6 Pokemon. Please note that the
user should have an option to choose less than 6 Pokemon if they choose to do
so
• choose_randomly, to generate a team randomly chosen Pokemon. This should be
equal to the TEAM_LIMT (normally 6).
o Update: This method has been provided to you in the scaffold.
• regenerate_team(battle_mode, criterion=None), to heal all of the pokemon to
their original HP while preserving their level and evolution. This should also
assemble the team according to the battle mode (discussed later)
• assemble_team, to place your pokemon in the appropriate ADT when a battle
mode is selected (you will need to leave this empty right now but you will fill this
in later in the next task)
• special , which takes different effects based on the type of battle, which will be
covered in the next task
• __getitem__, to retrieve a Pokemon at a specific index of the team
• len(team), should return the current length of the team
• str(team) , should return a string with the current members of the team with
each member on a new line
In a battle, Pokemon will be retrieved from the team and used in battle. If a Pokemon is
swapped out, then it is added back into the team.
What is a Trainer?
A trainer is the holder of a Pokemon team. The trainer has a name, a team and a
Pokedex. A Pokedex registers if a trainer has seen a particular pokemon, whether it be
in their own team or during battle.
The class Trainer should have the following methods:
• __init__, which should take the name as an argument and set the Trainer's
name, initialise a new PokeTeam and also a Pokedex.
• pick_team, which should pick a team based on the mode that is supplied to the
method as an argument. Pick team can only have the values 'Random' or
'Manual'. You should return an error if one of these options is not chosen
• get_team, which should return the current PokeTeam
• register_pokemon, which should register a pokemon (by its PokeType) as seen on
the trainer's Pokedex
• get_pokedex_completion, which should return a rounded float ratio of the
number of different TYPES of pokemon seen vs the total number of TYPES of
pokemon available rounded to 2 decimal points. For this point, two FIRE type
pokemon count as the exact same
• str(trainer), should return a string of the following format: Trainer
Pokedex Completion: %
You need to convert your pokedex completion to a percentage here by
multiplying it by 100
Battle Logic
Commencing The Battle
After being positioned, the teams battle. Battling involves attacking and defending,
after which HP is lost according to the attack stat and the damage after being attacked
stat. Remember to use the Pokedex multiplier here!
The battle begins with the first Pokemon of each team (positioned in the right order)
getting into battle. The battle between two units (say P1 and P2) proceeds as follows:
• If the speed of unit P1 is greater than that of P2, P1 attacks and P2 defends.
• If the speed of unit P2 is greater than that of P1, P2 attacks and P1 defends.
• If the speeds of P1 and P2 are identical, then both attack and defend
simultaneously, regardless of whether one, or both, would faint in combat.
Alternately after this initial attack, if the defending Pokemon has not fainted
(that is, it still has HP > 0), then they will retort with their own attack to the first
Pokemon. Once this has happened, there can only be three scenarios:
• One of the two Pokemon faints. In this case, the other Pokemon gains 1 level.
The other Pokemon then goes back to the team.
• Both Pokemon faint. In this case, we just leave their carcasses on the battlefield
and move on.
• Both Pokemon are still alive after they have attacked each other. In this case,
they both lose 1 HP. If they are still alive after losing this 1 HP, they are sent back
to their teams. If a Pokemon faints here due to losing this 1 HP and the other
Pokemon is alive, such a Pokemon still gains 1 level.
Battle Multipliers
As you may remember, in Pokemon Base, we used a multiplier based on the type of
Pokemon that is attacking and the type of Pokemon that is defending.
While battling, we are going to introduce another multiplier, which grows stronger with
trainer experience.
When you are attacking another pokemon, multiply the attack damage with the ratio
between the pokedex completion of the attacker vs the pokedex completion of the
defender.
For example, if Pokemon p1 that belongs to the trainer t1 is attacking Pokemon p2 that
belongs to the trainer t2 then:
attack_damage = ceil(p1.attack(p2) *
(t1.get_pokedex_completion()/t2.get_pokedex_completion())
This attack damage can then be used in the defend method of the defending pokemon
Ending the Battle
The game ends when at least one of the teams is empty (i.e., it has no usable
Pokemon).
[TASK 3] Battle!
A reminder that use of inbuilt lists, dictionaries, sets are banned, and using less suited data structures
will result in loss of marks.
Finally, we make it to the Battles :)
Battle Modes
Before we commence the battle class, we need to understand how battle modes work.
There are overall 3 battle modes available:
Set Mode
In a Set mode, we will follow a 'King of the Hill' style of combat. In this mode, a
particular Pokemon from one trainer's team keeps fighting until its fainted (health <=
0). The pokemon gains experience and levels up the same if it is able to faint the
pokemon from the other team, but it keeps fighting until it is exhausted. Here is a
representation of how this may occur:
Note: The initial composition of the team should be in reverse order. That is, the first Pokemon to
battle should be the last Pokemon that was selected.
You have been given certain Abstract Data Types (ADTs) in the data_structures folder,
one of which can be used for this task. Think about what you need to accomplish and
then pick a suitable ADT.
Rotating Mode
We will now focus on the rotating mode for battle. In this mode, a Pokemon fights a
round, and then is sent to the back of the team, making the next pokemon in the party
fight the next round. The battle ends when at least one of the teams is empty. You
should again choose one of the ADTs provided to you to make this mode work the way
it is intended.
Here is a pictorial representation of how this may look:
Optimised Mode
Now, things get a little interesting in the optimised mode! In this mode, the user gets to
choose an attribute to order their team. They can choose between Level, HP, Attack,
Defence and Speed. This order will be maintained throughout the battle, even when
the stats change after each round. The battle mode for this mode is 2. And, once again,
you need to choose from the given ADTs and once you have chosen a suitable ADT.
You need to add a new method assign_team method to assign the order of the team
based on the chosen attribute.
Improvement to the PokeTeam
First and foremost, you will need to complete the assemble_team method in the
PokeTeam class. Now that you have chosen your prefered ADTs, you can finish off the
functionality of this method. You will need to replace the self.team attribute of the
PokeTeam with your ADT of choice.
Next, complete the special method in the PokeTeam. Here are the details:
If special is called on a PokeTeam, the following should occur based on the battle
mode:
• SET MODE: If special is called during battle, this should reverse the first half of
the team
• ROTATE MODE: If special is called during battle, this should reverse the bottom
half of the team
• OPTIMISE MODE: it toggles the sorting order (from ascending to descending and
vice-versa)
Implement the Battle class
Most of the battle logic has already been discussed in the Battle Logic slide so here are
the basics of the Battle class:
In battle.py, we have the Battle class, with which you'll need to implement the
following methods:
• __init__, which initialises the battling trainers, the battle mode, and the
criterion; if applicable.
• _create_teams, which turns the PokeTeams from the two trainers into
appropriate data structures based on the mode supplied to the battle as an
initial argument.
• commence_battle, which calls the appropriate battle method from the 3 based on
the battle mode set in the initialiser. This method returns the winning trainer or
None; in the case when its a draw
The team's methods will need to be updated to support the new team formations. For example, you
will need to revisit getitem, len and str.
[TASK 4] Battle Tower
A reminder that use of inbuilt lists, dictionaries, sets are banned, and using less suited data structures
will result in loss of marks.
The final task! In the monster battles game, what's better than a battle between two
Trainers? Why multiple of course!
In the battle tower, the player (with a team of Pokemon), faces a gauntlet of teams of
Pokemon to battle.
Each team (both the player's team and the enemy teams) have some amount of lives.
The enemy teams take it in turns to battle the player's team, and the result is either a
win/loss or draw. The losing team loses a life, and in the result of a draw both teams
lose a life.
The order in which enemy teams face up against the player team is determined in the
following manner:
• Some initial ordering for the enemy teams is decided.
• After all enemy teams have fought the player team, then of the remaining
enemy teams, those with at least 1 life will fight the player again, following the
same initial ordering as before.
• Before every battle, regenerate_team is called on both teams to heal the entire
team and revive fainted monsters.
So for example, suppose we have 3 enemy trainers, A B and C, each with 2, 1 and 3
lives.
Then in the order of play, assuming that the player wins every battle:
1. We face trainer A, B and then C
2. We face trainer A, then C
3. We face trainer C
The battle tower ends when there are no enemy trainer lives left, or no lives left for the
player team, or both.
Your task is to implement the following functionality in tower.py:
BattleTower Class
• __init__ method: Initialises the class.
• set_my_trainer: Sets the player team for the battle tower, and generates
between MIN_LIVES and MAX_LIVES lives
• generate_enemy_trainers: Randomly generates n enemy teams (n is passed as a
parameter). All teams must use selection_mode RANDOM and all battle are
fought with battle mode ROTATE. Generate each team a number of lives
between MIN_LIVES and MAX_LIVES, after each team is generated but before the
next team is generated.
• battles_remaining: Returns True if there are more battles to be had, False if
either the player or all enemy teams have ran out of lives.
• next_battle: Simulates one battle in the tower, between the player team and
the next enemy team. Returns 5 values: The battle result, the player trainer, the
enemy trainer, the player lives remaining after the battle, and the enemy lives
remaining after the battle.
• enemies_defeated, you should keep a counter of the number of enemy lives
taken by the player, which this method should return.