How can I use a probability distribution in python class?

Question

Say I have the following class:

class Vehicle:

    def __init__(self, pevtype):
        self.pevtype = pevtype

How can I write a function which uses a probability distribution to determine whether the vehicle is an EV or a PHEV?

For example, the function setVehicle() would enable:

>>> v1.pevtype = 'EV'
>>> v2.pevtype = 'PHEV'

Answer 1

You could use numpy.random.choice. It takes a list of items that you want to chose from, and you can pass it the probability associated with each item as well. In the following example, I stored the information in a dict, where the keys are the items you want to chose from, and the values are the respective probabilities:

import numpy as np


class Vehicle:
    def __init__(self, pevtypes):
        self.pevtype = np.random.choice(
            list(pevtypes), p=list(pevtypes.values())
        )

car_types = {'EV': 0.3, 'PHEV': 0.7}

# for a single car
car = Vehicle(car_types)

print(car.pevtype)

# for 2 or more cars e.g. like this
cars = [Vehicle(car_types) for _ in range(3)]