Files Answer to exercise 3
from __future__ import print_function
import sys
start = int(sys.argv[1])
end = int(sys.argv[2])
with open(sys.argv[3]) as f:
lines = f.readlines()
nlines = len(lines)
if start < 0:
start = 0
elif start >= nlines:
start = nlines-1
if end >= nlines:
end = nlines-1
elif end < 0:
end = 0
if end >= start:
for line in lines[start-1:end]:
print(line, end="")
else:
for line in lines[start-1:end-1:-1]:
print(line, end="")