There are multiple diff styles and different functions exist for them in the difflib library. unified_diff, ndiff and context_diff.

If you don't want the line number summaries, ndiff function gives a Differ-style delta:

import difflib

f1 = '''1
2
3
4
5'''
f2 = '''1
3
4
5
6'''

diff = difflib.ndiff(f1,f2)

for l in diff:
    print(l)

Output:

  1
- 2          
  3          
  4          
  5   
+ 6

EDIT:

You could also parse the diff to extract only the changes if that's what you want:

>>>changes = [l for l in diff if l.startswith('+ ') or l.startswith('- ')]

>>>for c in changes:
       print(c)
>>>
- 2
+ 6

Does difflib.unified_diff do want you want? There is an example here.

The original link is broken. There is an example here

Here is a quick example of comparing the contents of two files using Python difflib...

import difflib

file1 = "myFile1.txt"
file2 = "myFile2.txt"

diff = difflib.ndiff(open(file1).readlines(),open(file2).readlines())
print ''.join(diff),