Python3, create multiple objects of a class at once

Question

i want to create multiple objects with diferent names at once.

For example

class Car:
    def __init__(self, color):
        self.color = color

And i need to create n objects when the program first run

car_1 = Car("blue")
car_2 = Car("Red")
#...
car_n = Car("color_n")

Is there a way to do this in python3? All the things i've tried just create one object and change its name or overwhite the objects information o simply fails at running. I can't use exec() or eval()

Thanks

Extra: I need the thing before because i need to store n Client's information whenever i run the program to work with it (that info is stored in a .csv file). Do i need to do the thing i mentioned before or is there another way to deal with this kind of data management?

Possible duplicate of [How do I create a variable number of variables?](https://stackoverflow.com/questions/1373164/how-do-i-create-a-variable-number-of-variables) — jonrsharpe, Aug 14 '17 at 19:08
Don't do this. Use a data structure such as a `list` or `dict` to hold your objects. Trying to dynamically create variables is asking for trouble and headaches. — Christian Dean, Aug 14 '17 at 19:10

alvarez · Accepted Answer · 2017-08-15T11:11:58.773

1

You can create a list of Cars objects, by list comprehension

class Car:
    def __init__(self, color):
        self.color = color
    def __repr__(self):
        return '{}({!r})'.format(self.__class__.__name__, self.color)

colors=['red', 'blue', 'green',]
cars_objects = [Car(color) for color in colors]
print(cars_objects)

return

[Car('red'), Car('blue'), Car('green')]

__repr__ function in Car Class creates a "more readable" (and parseable) representation of Car object instead of "<__main__.Car object at 0x7f5b38a2c400>"

edited Aug 15 '17 at 11:11

answered Aug 14 '17 at 19:54

alvarez

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3
9

1

Consider making the `repr` version parseable; for instance, `'{}({!r})'.format(self.__class__.__name__, self.color)`. This would show e.g. `Car('red')`. Makes it easier when replicating values for debugging and such. From `__repr__` documentation: [If at all possible, this should look like a valid Python expression that could be used to recreate an object with the same value (given an appropriate environment).](https://docs.python.org/3/reference/datamodel.html#object.__repr__) – Yann Vernier Aug 15 '17 at 11:03
@YannVernier You're absolutely right for this case. I edited my answer. Now the value returned by __repr__ could be used to recreate Car objects. – alvarez Aug 15 '17 at 11:23

Python3, create multiple objects of a class at once

1 Answers1