realtime log position to txt use python script

Can someone help me create a Python script to record positions in the event of a power loss or LinuxCNC error?

I plan to create an external real-time position logger with an update interval of 0.001 seconds. I use this feature for a wirecut machine. I'm using a Python script and have tried activating log_position_to_txt.py with the M-code command, but the position logging process results in a code overflow, causing the .txt file to grow uncontrollably.

Here's the code for log_position_to_txt.py:

##############################
#!/usr/bin/env python2.7
import linuxcnc
import time

stat = linuxcnc.stat()

with open("position-log.txt", "w") as outfile:

while True:

stat.poll()
x,y,z,a,b,c,u,v,w = stat.actual_position

outfile.write("X ")
outfile.write("{:.4f}\n".format(x))
outfile.write("Y ")
outfile.write("{:.4f}\n".format(y))

time.sleep(0.001)
####################################


Can someone help me fix my Python script so that... position recording does not result in code accumulation?

better use python3

Thanks for your help. But position-log.txt doesn't show up to record.

I'm using LinuxCNC 2.8.4 Debian Buster.

LinuxCNC already has that feature, it is called POSITION_FILE and should be added to the ini file in the [TRAJ] section, something like this
POSITION_FILE = last_position.txt

I've tried POSITION_FILE, but it can only save the position when linuxcnc is closed normally. When my PC is suddenly turned off, such as due to a power outage or linuxcnc error, POSITION_FILE doesn't save the last position of the machine movement.