Lesson 5: Writing Reusable and Self-explanatory Programs > Switching branches | Python Programming | Department of Computing

Lesson 5

Writing Reusable and Self-explanatory Programs

Chapter 8: git branch

Switching branches

face Josiah Wang

If you check your branchtest directory, you should see both python.txt and idea.txt there.

user@MACHINE:~/branchtest$ ls
idea.txt  python.txt

Now, let us switch back to the main branch.

user@MACHINE:~/branchtest$ git checkout main
Switched to branch 'main'
user@MACHINE:~/branchtest$ git branch
  killer
* main

As expected, you’re back in the main branch.

Now, if you look at your branchtest, you should find that your killer idea.txt file that you created earlier has disappeared! 😱😱😱

user@MACHINE:~/branchtest$ ls
python.txt

Calm down. It’s fine. The file still exists. You are looking at the latest snapshot of the main branch, which did not have idea.txt. You only created it in the newer killer branch. But just to assure yourself, switch back to the killer branch to check!

user@MACHINE:~/branchtest$ git checkout killer
Switched to branch 'killer'
user@MACHINE:~/branchtest$ ls
idea.txt  python.txt

Ok, idea.txt is still there. 😌

via GIPHY

Now, switch back to the main branch.

user@MACHINE:~/branchtest$ git checkout main
Switched to branch 'main'

While you still want to experiment with your killer idea, you still need to earn a living doing pragmatic things in the main branch. So edit python.txt, and add something else (I’ll add a c).

a
b
c

Add/commit the updated file to the main branch.

user@MACHINE:~/branchtest$ git add -u
user@MACHINE:~/branchtest$ git commit -m "Added c to python.txt"
[main 76917d8] Added c to python.txt
 1 file changed, 1 insertion(+)
user@MACHINE:~/branchtest$ git log --oneline
76917d8 (HEAD -> main) Added c to python.txt
6ca445c Added b to python.txt
620496e Initial commit

Interestingly, when you look at the git log, it only shows you the commit history for the main branch. You will not see the commit for idea.txt from earlier by default.

To view all commits, add --all as an option to git log. I’ve also added --graph to show a visualisation of the branches.

user@MACHINE:~/branchtest$ git log --oneline --all --graph
* 76917d8 (HEAD -> main) Added c to python.txt
| * 9d34c0a (killer) Added a new file idea.txt
|/
* 6ca445c Added b to python.txt
* 620496e Initial commit

Hopefully the graph makes sense. It shows you both your branches.