Find shortest matches between two strings
This regex should match what you want:
(start((?!start).)*?end)
Use re.findall method and single-line modifier re.S to get all the occurences in a multi-line string:
re.findall('(start((?!start).)*?end)', text, re.S)
See a test here.
Do it with code - basic state machine:
open = False
tmp = []
for ln in fi:
if 'start' in ln:
if open:
tmp = []
else:
open = True
if open:
tmp.append(ln)
if 'end' in ln:
open = False
for x in tmp:
print x
tmp = []