How to simulate more train objects running simultaneously in Python?

Question

Good evening,

I am trying to make my first simulation, modelling metro network. I discovered I was probably very naive. Can someone point me in the right direction?

I wanted to have 6 trains on 3 metro lines (in opposite directions) running silently in the background in endless loops back and forth in each line. Then I thought the user could ask a question where is a particular train "right now" and would get its position for instance.

Here is the code (the problematic part):

from classes import Train
from objects import lineA, lineB, lineC

train1 = Train(1464, lineA[0])
train2 = Train(1464, lineA[-1])
train3 = Train(1464, lineB[0])
train4 = Train(1464, lineB[-1])
train5 = Train(1464, lineC[0])
train6 = Train(1464, lineC[-1])


train1.move(lineA)
train2.move(list(reversed(lineA)))

train3.move(lineB)
train4.move(list(reversed(lineB)))

train5.move(lineC)
train6.move(list(reversed(lineA)))

where moving is defined like:

class Train:
    def __init__(self, places, position):
        self.places = places
        self.position = position

    def move(self, line):

        forth = True
        while True:
            for i in range(len(line)):
                temp = line if forth else list(reversed(line))
                position = temp[i]
                time.sleep(2)
            forth = not forth

I suppose the problem is that the program executes only the first function train1.move(lineA) which is an endless loop so nothing after that gets executed. I am not sure how to proceed...