A Python 3.6 program that splits one file to some .txt documents with specified length in lines

pages.py

#!/usr/bin/env python3
from urllib.request import urlopen
def slicefile(data, start, end):
	import itertools
	lines = data.splitlines()
	return itertools.islice(lines, start, end)

def pages(data, lines):
	count = 0
	start, end = 0, lines
	while end <= len(data.splitlines()):
		aline = list(slicefile(data, start, end))
		with open('page-{}.txt'.format(count), 'w') as x:
			for line in aline:
				x.write(line + '\n')
			x.close()
		start, end = end, end+lines
		count += 1

def in_web(filename, lines):
	response = urlopen(filename)
	content = response.read()
	pages(content, lines)
def in_disk(filename, lines):
	pages(open(filename).read(), lines)


from argparse import *

parser = ArgumentParser(description='Convert file to pages.')
parser.add_argument('-w', '--web', help='Find file in the web.', action='store_true')
parser.add_argument('file', help='File name or URL')
parser.add_argument('lines', help='Number of lines in one page', type=int)
args = parser.parse_args()
if args.web:
	in_web(args.file, args.lines)
else:
	in_disk(args.file, args.lines)