Python StopWatch milliseconds

(Stopwatch) Design a class named StopWatch. The class contains:
■ The private data fields startTime and endTime with get methods.
■ A constructor that initializes startTime with the current time.
■ A method named start() that resets the startTime to the current time.
■ A method named stop() that sets the endTime to the current time.
■ A method named getElapsedTime() that returns the elapsed time for the stop watch in milliseconds.
Write a test program that measures the execution time of adding numbers from 1 to 1,000,000.

from datetime import datetime

Import time
class StopWatch():
    now = datetime.now()
    def __init__(self,  endTime = 0, startTime = datetime.now()):
        self.__startTime = startTime
        self.__endTime = endTime

    def getStart(self):
        return self.__startTime
    def getEnd(self):
        return self.__endTime
    def start(self):
        self.__startTime = round(time.time()*1000)
        return self.__startTime
    def stop(self):
        self.__endTime = round(time.time()*1000)
        return self.__endTime

    def getElapsedTime(self):
        etime = StopWatch.getEnd(self) - StopWatch.getStart(self)
        return etime
    def loop(self):
        count = 0
        for i in range(1000000):
            count += 1
        return count

def main():
    s = StopWatch()
    print('Start time: ', s.start())
    print(s.loop())
    print('Stop time: ', s.stop())
    print('The execution time of adding numbers from 1 to 1,000,000 is: ', s.getElapsedTime())

main()

SOLUTION:

Start time:  830213
1000000
Stop time:  982221

The execution time of adding numbers from 1 to 1,000,000 is:  152008  milliseconds!