>>> res=''
>>> for f in os.listdir(path):
	text = open(f, 'r').read()
	res += '\n'.join(re.findall('<fpc4:Str dt:dt="string">(.+)</fpc4:Str>', text)) + '\n'

>>> result = open('results.txt', 'w')
>>> result.write(res)
>>> result.close()
>>>