CODEWITHSUNDEEP
pythondifflib
kev
kev

Reputation: 9765

Get standard gnu diff output from Python's difflib?

Is there any way to get the following output (especially the 1,4c1,4 syntax) from Python's difflib?

diff foo baz 
1,4c1,4
< 'asdf'
< 'asdf'
< 'asdf'
< 'asdf'
---
> asdf
> asdf
> asdf
> asdf

Upvotes: 4

Views: 1476

Answers (2)

mitlenatch
mitlenatch

Reputation: 21

There's a good implementation here: https://github.com/glanois/code/blob/master/python/ppt/diff.py

Its header comment says:

This class produces differences in the POSIX default format (see http://www.unix.com/man-page/POSIX/1posix/diff/), which is the same as the Gnu diff "normal format" (see http://www.gnu.org/software/diffutils/manual/diffutils.html#Normal).

I tested it with python 2.7, producing the following output for your example:

$ python diff.py foo baz
1,4c1,4
< 'asdf'
< 'asdf'
< 'asdf'
< 'asdf'
---
> asdf
> asdf
> asdf
> asdf

Upvotes: 2

Loknar
Loknar

Reputation: 1189

You can without doupt recreate the desired syntax output using difflib but it might take some devious steps to simulate perfectly.

If this specific output syntax is not necessary you might consider the following solution:

import difflib
def generate_readable_diff_string(str_a, str_b):
    return ''.join(
        difflib.unified_diff(
            str_a.splitlines(True),
            str_b.splitlines(True),
            lineterm='\n'
        )
    )

For your foo and baz this function produces the following result:

--- 
+++ 
@@ -1,4 +1,4 @@
-'asdf'
-'asdf'
-'asdf'
-'asdf'
+asdf
+asdf
+asdf
+asdf

Upvotes: 1

Related Questions