python - how to do a git diff of current commit with last commit using gitpython?

5
votes

I am trying o grasp gitpython module, 

hcommit = repo.head.commit
tdiff = hcommit.diff('HEAD~1')

but tdiff = hcommit.diff('HEAD^ HEAD') doesn't work !! neither does ('HEAD~ HEAD').,

I am trying to get the diff output !

5
pythongitgitpython
I admit to never having used the gitpython code, but it seems obvious that if hcommit is repo.head.commit, it's bound to that particular commit, and thus hcommit.diff means "diff that particular commit, against something else". To get diffs of two arbitrary commits, you'd have to choose some other starting-point. - torek

5 Answers

8
votes
import git

repo = git.Repo('repo_path')
commits_list = list(repo.iter_commits())

# --- To compare the current HEAD against the bare init commit
a_commit = commits_list[0]
b_commit = commits_list[-1]

a_commit.diff(b_commit)

This will return a diff object for the commits. There are other ways to achieve this as well. For example (this is copy/pasted from http://gitpython.readthedocs.io/en/stable/tutorial.html#obtaining-diff-information):

```

    hcommit = repo.head.commit
    hcommit.diff()                  # diff tree against index
    hcommit.diff('HEAD~1')          # diff tree against previous tree
    hcommit.diff(None)              # diff tree against working tree

    index = repo.index
    index.diff()                    # diff index against itself yielding empty diff
    index.diff(None)                # diff index against working copy
    index.diff('HEAD')              # diff index against current HEAD tree

```

3
votes

I figured out how to get the git diff using gitPython.

import git
repo = git.Repo("path/of/repo/")

# the below gives us all commits
repo.commits()

# take the first and last commit

a_commit = repo.commits()[0]
b_commit = repo.commits()[1]

# now get the diff
repo.diff(a_commit,b_commit)

Voila !!!

2
votes

To get the contents of the diff:

import git
repo = git.Repo("path/of/repo/")

# define a new git object of the desired repo
gitt = repo.git
diff_st = gitt.diff("commitID_A", "commitID_B")
1
votes

For a proper solution (without using git command callback), you have to use create_patch option.

To compare current index with previous commit:

diff_as_patch = repo.index.diff(repo.commit('HEAD~1'), create_patch=True)
print(diff_as_patch)
0
votes

Sorry to dig up an old thread... If you need to find out which files changed, you can use the .a_path or .b_path attribute of a diff object depending on which one you feed it first. In the example below I'm using the head commit as a so I look at a.

e.g:

# this will compare the most recent commit to the one prior to find out what changed.

from git import repo

repo = git.Repo("path/to/.git directory")
repoDiffs = repo.head.commit.diff('HEAD~1')

for item in repoDiffs:
    print(item.a_path)