import os

file = open("temp", "w")
file.write("before the fork") # 15
#file.flush()

if os.fork() == 0: # in the child
    print("child: {}".format(file.tell()))
    print("child: {}".format(file.tell()))
else: # in the parent
    print("parent: {}".format(file.tell()))
    print("parent: {}".format(file.tell()))

file.close()