I would like to modify a file containing a hex dump. There are 33 lines which contain strings like this:

```none
0000000000000000b00b8000c7600795
0001906da451000000008fac0b000000

```

I would like to put two spaces after every two characters, like this:

```
00 00 00 00 00 00 00 00 b0 0b 80 00 c7 60 07 95

```

So far I've made this script that works, but it puts two spaces in each character. I can't see what parameter I can use with `.join()` to make it every two characters:

```
import os

os.rename( 'hex_dump.txt', 'hex_dump.old' )

destination = open( 'hex_dump.txt', "w" )
source = open( 'hex_dump.old', "r" )
for line in source:
    if len(line) > 2:
        destination.write("  ".join(line))
source.close()
destination.close()

```