double for loops in python

Question

I am trying to get a list of file names in order. Something like

files-1-loop-21
files-1-loop-22
files-1-loop-23
files-1-loop-24
files-2-loop-21
files-2-loop-22
files-2-loop-23
.
.
.
and so on

As for testing I have written python code as below:

code sample_1:

for md in range(1,5):
   for pico in range(21,25):
      print md, pico

It gives me pair of number such as:

  `1 21
   1 22
   1 23
   1 24
   2 21
   2 22
   2 23
   2 24
   3 21
   3 22
   3 23
   3 24
   4 21
   4 22
   4 23
   4 24

`

if I use:

code sample_2:

 for md in range(1,5):
   for pico in range(21,25):
  print "file-md-loop-pico"

I get

  files-md-loop-pico
  files-md-loop-pico
  files-md-loop-pico
  files-md-loop-pico
  files-md-loop-pico
  files-md-loop-pico
  files-md-loop-pico

How (code sample_2) should be altered to get the file lists as I wanted (as shown in the beginning of this post) in python?

Thanks in advance.

Regards

Answer 1

Try this:

for md in range(1,5):
   for pico in range(21,25):
      print "file-{0}-loop-{1}".format(md, pico)

Or:

from itertools import product
for md, pico in product(range(1,5), range(21,25)):
    print "file-{0}-loop-{1}".format(md, pico)