My problem is that i want to create x amount of instances of a class and store the order they were c-CodePudding

I have a question, my problem is that i want to create x amount of instances of a class and store(inside the instance) the order they were created in. Is there a way that i can do that because i tried but could not do anything and im new to python i just started programming, and this is my first language so please be tolerant.

MaxAnts = 100

class Ant:
  def __init__(self,id):
  self.id = id
  #then i will use the id to do math

i = 0
if i <= MaxAnts:
  i  = 1
  i = Ant(i)

But for some reason this doesn't work, i dont know why, please clarify the problem if you know it.

CodePudding user response：

The class itself can give ids to its instances.

class Ant:
    counter = 0  # counter is a class variable

    def __init__(self):
        cls = type(self)
        self.id = cls.counter  # id is an instance variable
        cls.counter  = 1

# example:
a = Ant()
b = Ant()
c = Ant()
print(a.id, b.id, c.id) # prints: 0 1 2

CodePudding user response：

Using list comprehension as described in the comments is not a bad way to go but I'll put this here just to give you a introduction to lists.

MaxAnts = 100

class Ant:
  def __init__(self,id):
  self.id = id
  #then i will use the id to do math

ants = [] # or ants = list() , same thing
i = 0
if i <= MaxAnts:
  i  = 1
  ants.append(Ant(i))

The only wierd thing here is that because lists are 0 indexed ants[0].id will be 1 and ant[99].id will be 100. If you do ants = [Ant(i) for i in range(MaxAnts)] you will have your index lined up with your ids, ants[7].id = 7. But you could get the same effect by putting i =1 after ants.append(Ant(i)) instead of the line before.

CodePudding user response：

To create x amount of instances of some class you would need to use some form of iteration and append them to a collection that you would be able to access.

MaxAnts = 100

class Ant:
  def __init__(self,id):
  self.id = id
  #then i will use the id to do math

ants = []  # A list to store your ants 
for i in range(MaxAnts):  # Iterating i from 0 to MaxAnts - 1
    ant = Ant(i)  # Creating your new ant with the i as a parameter
    ants.append(ant)  # Adding your new ant to the ants list

Since by default 'range' gives you a range from 0 to argument - 1, in case you want to start your order from 1, you should start your iteration from 1, and end it on MaxAnts:

for i in range(1, MaxAnts   1):  # Iterating i from 1 to MaxAnts

More on lists: https://docs.python.org/3/tutorial/datastructures.html

More on range: https://docs.python.org/3/library/functions.html#func-range