Python zählt auf und ab

from time import sleep, time

can_run = True
the_number = 0

end_number = 11 #you can change the number to be last counted

while can_run:
    print(the_number)
    sleep(1)
    the_number = the_number + 1
    if  the_number == end_number: 
        can_run = False
        can_walk = True
        end_number = 0
        while can_walk:
            the_number = the_number - 1
            print(the_number)
            sleep(1)
            if the_number == end_number:
                can_walk = False
dl.guy