Diff

git diff Old_commit_id New_commit_id > my.patch
git apply my.patch

Format-patch

patch the latest n commits.

git format-patch -n

switch to another branch, apply these patches.

git am 000x-xxx.patch

when conflict:

git apply --reject 000x-xxx.patch

This command will create xxx.py.rej files which contains the hunk that failed.

after fix these conflict files...

git add <files>

git am --resolved

git rebase -i <commit SHA-1>

squash (s for short): which melds the commit into the previous one (the one in the line before)
fixup (f for short): which acts like “squash”, but discards this commit’s message

git stash

git stash pop