Creating a list of objects from a list of lists

Question

I've just started to learn Python. I have a list of lists where each element is a list and looks something like this: ['1', '2', '3']. I have a created a class like this:

class Car(object):
    def __init__(self, a, b=0, c=0):
        self.a = a
        self.b = b
        self.c = c
    def setABC(self, a, b, c):
        self.a = a
        self.b = b
        self.c = c

How do I create a new list where each element is an instance of this class, instead of the original list members?

I have tried something like this, but obviously it didn't work:

cars = cars.append(Car(cars[0], cars[1], cars[2]))

Also, I tried this:

cars = [Car(x.a, x.b, x.c) for x in cars]

Answer 1

You should unpack the nested list to create class object. You may create the list of Car objects via using list comprehension as:

cars = [Car(*props) for props in properties_list]

where properties_list is the list holding the properties you want to create your car with.

For example, if properties_list is like:

properties_list = [[1, 2, 3], [4, 5, 6]]

then cars will hold the list of Car objects as:

cars = [
    Car(a=1, b=2, c=3),
    Car(a=4, b=5, c=6)
]