No program is executed in python

I am programming in python the use of the supersonic sensor HY-SRF05 using a Raspberry Pi 3. The program does not give an error, but it does not show the distance when executed, if I remove the class and the methods and leave only the linear code , it works correctly but I require the use of methods for future work issues. I need to show the distance. My code is as follows:

import mysql.connector
import requests
import RPi.GPIO as GPIO   
import time                

GPIO.setwarnings(False)
GPIO.setmode(GPIO.BCM)    
GPIO_TRIGGER = 25          
GPIO_ECHO    = 7          
GPIO.setup(GPIO_TRIGGER,GPIO.OUT) 
GPIO.setup(GPIO_ECHO,GPIO.IN)     
GPIO.output(GPIO_TRIGGER,False)   

class Execute:

    def ObtenerDistancia(self):
        temperature = 20
        speedSound = 33100 + (0.6*temperature)
        GPIO.setup(GPIO_TRIGGER,GPIO.OUT)  
        GPIO.setup(GPIO_ECHO,GPIO.IN)     
        GPIO.output(GPIO_TRIGGER, False)
        time.sleep(0.5)# Allow module to settle
        GPIO.output(GPIO_TRIGGER, True)
        time.sleep(0.00001)# Wait 10us
        GPIO.output(GPIO_TRIGGER, False)
        start = time.time()
        while GPIO.input(GPIO_ECHO)==0:
            start = time.time()
        while GPIO.input(GPIO_ECHO)==1:
            stop = time.time()
        elapsed = stop-start
        distance = elapsed * speedSound
        distance = distance / 2
        print("Distance : {0:5.1f}".format(distance))
        GPIO.cleanup()
        return distance


x = Execute()
xDis = x.ObtenerDistancia

while True:
    print (xDis())

My "linear" code:

import time
import RPi.GPIO as GPIO

GPIO.setmode(GPIO.BCM)
GPIO_TRIGGER = 23
GPIO_ECHO    = 24
temperature = 20
speedSound = 33100 + (0.6*temperature)

print("Ultrasonic Measurement")
print("Speed of sound is",speedSound/100,"m/s at ",temperature,"deg")
GPIO.setup(GPIO_TRIGGER,GPIO.OUT)  
GPIO.setup(GPIO_ECHO,GPIO.IN)      
GPIO.output(GPIO_TRIGGER, False)
time.sleep(0.5)# Allow module to settle
GPIO.output(GPIO_TRIGGER, True)
time.sleep(0.00001)# Wait 10us
GPIO.output(GPIO_TRIGGER, False)
start = time.time()
while GPIO.input(GPIO_ECHO)==0:
    start = time.time()
while GPIO.input(GPIO_ECHO)==1:
    stop = time.time()
elapsed = stop-start
distance = elapsed * speedSound
distance = distance / 2
print("Distance : {0:5.1f}".format(distance))
GPIO.cleanup()