Pure Python way to apply a unified diff to a file?

Question

I've got a unified diff file (let's call it a patch). I need to open it, apply to a specified file and save the result back to the file. Same way as Unix patch tool does. I need a Python solution that I could easily call from my .py script, and so far I can't find any.

I've looked at https://code.google.com/p/google-diff-match-patch/wiki/API, and it looks like it can't do what I need. I also looked at https://github.com/techtonik/python-patch and https://github.com/matiasb/python-unidiff. python-patch seems to emulate the Unix patch util, but it's a command line tool and I don't understand how to call it from my .py script.

See my answer here: http://stackoverflow.com/a/40967337/431087 — Isaac Turner, Dec 05 '16 at 04:56

score 11 · Answer 1 · edited Oct 21 '21 at 16:45

11

Using python-patch:

import patch
pset = patch.fromfile(unified_diff_filename)
pset.apply()

If you want to apply to a stream / differently named output, you will have to make your own function (look how apply is doing it, or find def apply in the latest).

edited Oct 21 '21 at 16:45

Andreas Haferburg

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answered Jul 16 '15 at 07:15

bufh

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Last release in 2015. – Andreas Haferburg Oct 21 '21 at 17:04
*> Last release in 2015.* yes, but the repository is still updated and Python3 compatible. – bufh Mar 21 '22 at 08:45
It is not compatible with Python3.9+ – Jerzy Pawlikowski Mar 24 '22 at 14:18

Pure Python way to apply a unified diff to a file?

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