Python - how to find all intersections of two strings?

Question

How to find all intersections (also called the longest common substrings) of two strings and their positions in both strings?

For example, if S1=\"never\"

Answer 1

Batteries included!

The difflib module might have some help for you - here is a quick and dirty side-by-side diff:

>>> import difflib
>>> list(difflib.ndiff("never","forever"))
['- n', '+ f', '+ o', '+ r', '  e', '  v', '  e', '  r']
>>> diffs = list(difflib.ndiff("never","forever"))
>>> for d in diffs:
...   print {' ': '  ', '-':'', '+':'    '}[d[0]]+d[1:]
...
 n
     f
     o
     r
   e
   v
   e
   r