Ellen's Alien Game
10 Points
classes
Instructions
Ellen is making a game where the player has to fight aliens.
She has just learned about Object Oriented Programming (OOP) and is eager to take advantage of what using classes could offer her program.
To Ellen's delight, you have offered to help and she has given you the task of programming the aliens that the player has to fight.
1. Create the Alien Class
Define the Alien class with a constructor that accepts two parameters <x_coordinate> and <y_coordinate>, putting them into x_coordinate and y_coordinate instance variables.
Every alien will also start off with a health level of 3, so the health variable should be initialized as well.
>>> alien = Alien(2, 0)
>>> alien.x_coordinate
2
>>> alien.y_coordinate
0
>>> alien.health
3Now, each alien should be able to internally track its own position and health.
2. The hit Method
Ellen would like the Alien class to have a hit method that decrements the health of an alien object by 1 when called.
This way, she can simply call <alien>.hit() instead of having to manually change an alien's health.
It is up to you if hit() takes healths points to or below zero.
>>> alien = Alien(0, 0)
# Initialized health value.
>>> alien.health
3
# Decrements health by 1 point.
>>> alien.hit()
>>> alien.health
23. The is_alive Method
You realize that if the health keeps decreasing, at some point it will probably hit 0 (or even less!).
It would be a good idea to add an is_alive method that Ellen can quickly call to check if the alien is... well... alive. 😉
<alien>.is_alive() should return a boolean.
>>> alien.health
1
>>> alien.is_alive()
True
>>> alien.hit()
>>> alien.health
0
>>> alien.is_alive()
False4. The teleport Method
In Ellen's game, the aliens have the ability to teleport!
You will need to write a teleport method that takes new x_coordinate and y_coordinate values, and changes the alien's coordinates accordingly.
>>> alien.teleport(5, -4)
>>> alien.x_coordinate
5
>>> alien.y_coordinate
-45. The collision_detection Method
Obviously, if the aliens can be hit by something, then they need to be able to detect when such a collision has occurred.
However, collision detection algorithms can be tricky, and you do not yet know how to implement one.
Ellen has said that she will do it later, but she would still like the collision_detection method to appear in the class as a reminder to build out the functionality.
It will need to take a variable of some kind (probably another object), but that's really all you know.
You will need to make sure that putting the method definition into the class doesn't cause any errors when called:
>>> alien.collision_detection(other_object)
>>>6. Alien Counter
Ellen has come back with a new request for you. She wants to keep track of how many aliens have been created over the game's lifetime. She says that it's got something to do with the scoring system.
For example:
>>> alien_one = Alien(5, 1)
>>> alien_one.total_aliens_created
1
>>> alien_two = Alien(3, 0)
>>> alien_two.total_aliens_created
2
>>> alien_one.total_aliens_created
2
# Accessing the variable from the class directly
>>> Alien.total_aliens_created
27. Creating a List of Aliens
Ellen loves what you've done so far, but she has one more favor to ask.
She would like a standalone (outside the Alien() class) function that creates a list of Alien() objects, given a list of positions (as tuples).
For example:
>>> alien_start_positions = [(4, 7), (-1, 0)]
>>> aliens = new_aliens_collection(alien_start_positions)
...
>>> for alien in aliens:
... print(alien.x_coordinate, alien.y_coordinate)
(4, 7)
(-1, 0)Ellen's Alien Game
10 Points
classes
Instructions
Ellen is making a game where the player has to fight aliens.
She has just learned about Object Oriented Programming (OOP) and is eager to take advantage of what using classes could offer her program.
To Ellen's delight, you have offered to help and she has given you the task of programming the aliens that the player has to fight.
1. Create the Alien Class
Define the Alien class with a constructor that accepts two parameters <x_coordinate> and <y_coordinate>, putting them into x_coordinate and y_coordinate instance variables.
Every alien will also start off with a health level of 3, so the health variable should be initialized as well.
>>> alien = Alien(2, 0)
>>> alien.x_coordinate
2
>>> alien.y_coordinate
0
>>> alien.health
3Now, each alien should be able to internally track its own position and health.
2. The hit Method
Ellen would like the Alien class to have a hit method that decrements the health of an alien object by 1 when called.
This way, she can simply call <alien>.hit() instead of having to manually change an alien's health.
It is up to you if hit() takes healths points to or below zero.
>>> alien = Alien(0, 0)
# Initialized health value.
>>> alien.health
3
# Decrements health by 1 point.
>>> alien.hit()
>>> alien.health
23. The is_alive Method
You realize that if the health keeps decreasing, at some point it will probably hit 0 (or even less!).
It would be a good idea to add an is_alive method that Ellen can quickly call to check if the alien is... well... alive. 😉
<alien>.is_alive() should return a boolean.
>>> alien.health
1
>>> alien.is_alive()
True
>>> alien.hit()
>>> alien.health
0
>>> alien.is_alive()
False4. The teleport Method
In Ellen's game, the aliens have the ability to teleport!
You will need to write a teleport method that takes new x_coordinate and y_coordinate values, and changes the alien's coordinates accordingly.
>>> alien.teleport(5, -4)
>>> alien.x_coordinate
5
>>> alien.y_coordinate
-45. The collision_detection Method
Obviously, if the aliens can be hit by something, then they need to be able to detect when such a collision has occurred.
However, collision detection algorithms can be tricky, and you do not yet know how to implement one.
Ellen has said that she will do it later, but she would still like the collision_detection method to appear in the class as a reminder to build out the functionality.
It will need to take a variable of some kind (probably another object), but that's really all you know.
You will need to make sure that putting the method definition into the class doesn't cause any errors when called:
>>> alien.collision_detection(other_object)
>>>6. Alien Counter
Ellen has come back with a new request for you. She wants to keep track of how many aliens have been created over the game's lifetime. She says that it's got something to do with the scoring system.
For example:
>>> alien_one = Alien(5, 1)
>>> alien_one.total_aliens_created
1
>>> alien_two = Alien(3, 0)
>>> alien_two.total_aliens_created
2
>>> alien_one.total_aliens_created
2
# Accessing the variable from the class directly
>>> Alien.total_aliens_created
27. Creating a List of Aliens
Ellen loves what you've done so far, but she has one more favor to ask.
She would like a standalone (outside the Alien() class) function that creates a list of Alien() objects, given a list of positions (as tuples).
For example:
>>> alien_start_positions = [(4, 7), (-1, 0)]
>>> aliens = new_aliens_collection(alien_start_positions)
...
>>> for alien in aliens:
... print(alien.x_coordinate, alien.y_coordinate)
(4, 7)
(-1, 0)