Python - unir txt cuando se actualiza

filenames = ['file1.txt', 'file2.txt', ...]

with open('path/to/output/file', 'w') as outfile:

    for fname in filenames:

        with open(fname) as infile:

            for line in infile:

                outfile.write(line)

filenames = ['file1.txt', 'file2.txt', ...]

with open('path/to/output/file', 'w') as outfile:

    for fname in filenames:

        with open(fname) as infile:

            outfile.write(infile.read())

import commands

import time

def getLines():

	linesFileA=commands.getoutput("wc -l file1.txt | awk {'print $1'}")

	linesFileB=commands.getoutput("wc -l file2.txt | awk {'print $1'}")

	return [linesFileA,linesFileB]

[linesFileA,linesFileB]=getLines()

while True:

	[actualFileA,actualFileB]=getLines()

	if actualFileA!=linesFileA or actualFileB!=linesFileB:

		filenames = ['file1.txt', 'file2.txt']

		with open('file', 'w') as outfile:

			for fname in filenames:

				with open(fname) as infile:

					for line in infile:

						outfile.write(line)

	time.sleep(5)