How do you increment file name in Python

Question

I'm trying to save a lot of data that needs to be separated in to different files like so data_1.dat data_2.dat data_3.dat data_4.dat

how do I implement this in python?

Answer 1

from itertools import count
filename = ("data_%03i.dat" % i for i in count(1))
next(filename)
# 'data_001.dat'
next(filename)
# 'data_002.dat'
next(filename)
# 'data_003.dat'

Answer 2

for i in range(10):
    filename = 'data_%d.dat'%(i,)
    print filename