ttpi

tt.py

#!/usr/bin/python2.7

from subprocess import check_output, STDOUT, CalledProcessError, call
from sys import argv, stdout, stdin
import fileinput

def run(func):
	if type(func) != type([]) and type(func) == type(""):
		func = func.split(' ')

	try:
		out = check_output(func, stderr=STDOUT)[:-1]
	except CalledProcessError as o:
		out = o.output[:-1]
	
	return out

ls = run('tmux ls')

if len(argv) == 1 and 'windows' in ls:
	print ls
	exit()

names = [i.split(":")[0]for i in ls.split("\n")]

if len(argv) == 1:
	argv = ['tt', '0']

if argv[1] in names:
	call(['tmux', 'attach', '-t', argv[1]])
	exit()

response = ''
while response != 'y':
	if not 'windows' in ls:
		out = 'no sessions, create one called "%s"? (y/n) '
	else:
		out = 'session "%s" does not exist, create it? (y/n) '
	stdout.write(out % argv[1])
	response = stdin.readline()[:-1].lower()
	if response == 'y':
		call(['tmux', 'new-session', '-s', argv[1]])
	elif response == 'n':
		exit()

I fixed up your indentation and added support for exiting gracefully on a captured C-c. My fork is at https://gist.github.com/nathyong/c18c91c1f16785e08293