python

tavi · 08-01-2011, 10:37 AM

Hi! I'm really new to Python. I'm writing a kind of virtual pet game at the moment in which 3 objects of the PetClass are created. But I was wondering if it is possible to make it so that the user decides how many objects of the class are created. So instead of something like

class PetClass(object):
def __init__(self, name, hunger, happiness, health):
self.name = name
self.hunger = hunger
self.happiness = happiness
self.health = health
print "Pet created"

pet1 = PetClass("Kitty", 0.4, 0.6, 0.4)
pet2 = PetClass("Puppy", 0.5, 0.3, 0.6)
pet3 = PetClass("Fishy", 0.2, 0.2, 0.2)

I would want to have the user decide how many (up to 10) pets they will have/objects to be created. I thought maybe a for loop would do it:

number = input("How many?")
for i in range(number):
# create an object in PetClass

but I don't know what to write after that; I think it's probably impossible to create different objects this way, as they'd all have the same variable name (e.g. each one would be pet1) ...which would make them the same object. I have no idea how to give them all different parameters as well.

Is there maybe a way to give each object its own name and parameters maybe via a list and a count variable, or is it impossible/too fiendishly complex?

JohnGraham · 08-01-2011, 11:03 AM

Quote:

Originally Posted by tavi

I think it's probably impossible to create different objects this way, as they'd all have the same variable name (e.g. each one would be pet1) ...which would make them the same object.

Look up arrays and use them. You might also want to either get user-defined values for each pet, or use random parameters (see the random module).

tavi · 08-01-2011, 01:36 PM

Do you know any good tutorial for using arrays with classes? They're not in my python book, and I can't really find anything so far that doesn't seem to assume prior knowledge of what arrays actually are.

I was hoping maybe there would be a way to turn a string element of a list into a variable name and use that to call an instance of the class...
e.g. mylist = ["pet1", "pet2", "pet3", "pet4"]

number = 3
for i in range(number):
count = 0
mylist[count] = PetClass()
count += 1

TobiSGD · 08-01-2011, 02:16 PM

Actually it would look something like that:

Code:

# Let user input the number of pets
number = input("How many?")
# Now create an empty array
yourpets = {}
# And fill it with the appropriate number of pets
for i in range(number):
    yourpets[i] = PetClass( ... )

Of course you have to generate the values for the creation of the objects randomly (or in any other way you want).

Note for the future: When posting code (especially Python code, where the correct indentation is essential for the understanding of the programs) please use code-tags. You will get them when you click on the #-symbol on top of the post-editor. This will make your posts much more readable and helps significantly in helping you.

Julian Andrews · 08-02-2011, 01:47 PM

Quote:

Originally Posted by TobiSGD

Actually it would look something like that:

Code:

# Let user input the number of pets
number = input("How many?")
# Now create an empty array
yourpets = {}

Really, a list is more appropriate here:

Code:

number = input("How many?")
pets = []
for i in range(number):
    pets.append(PetClass(...))

or, more succinctly:

Code:

input("How many?")
pets = [PetClass(...) for i in range(number)]

A dictionary involves unnecessary overhead, and is really only appropriate if you need key lookup.

TobiSGD · 08-02-2011, 02:03 PM

Quote:

Originally Posted by Julian Andrews

Really, a list is more appropriate here:

Code:

number = input("How many?")
pets = []
for i in range(number):
    pets.append(PetClass(...))

or, more succinctly:

Code:

input("How many?")
pets = [PetClass(...) for i in range(number)]

A dictionary involves unnecessary overhead, and is really only appropriate if you need key lookup.

You are right, of course. Long time since I have done something with Python, I should do a fresh-up before giving advice.