Copy a file every n seconds in python

With this code, I look at a source directory and copy it to the destination. But when I add a new file to the source directory, the copying is not done. And I want a file to be copied every second. This code is doing batch copying. Can you help me solve these two problems?

import os,os.path
import shutil
from os import listdir
from os.path import isfile, join

my_path = 'source_path'
target = 'target_path'


onlyfiles = [f for f in listdir(my_path ) if isfile(join(my_path , f))]

while True:
    for file in onlyfiles:
        if file.endswith(".gz"):           
            a = my_path + file
            b = target + file
            shutil.copy(a, b)
    time.sleep(1)

>Solution :

Ultimately, this solution can make it work

import shutil
import time
from pathlib import Path
import glob

my_path = 'source_path'
target = 'target_path'

onlyfiles = glob.glob(my_path+'/*.gz')

for file in onlyfiles:
    shutil.copy(file,  target + '/'+ Path(file).name)
    time.sleep(1)