Import github project into preexisting git project -

i'm working on flask app in local git repo. i've come across python script import project root github. i'm not sure how "pull in/import" script local repo, without affecting pre-existing code. can advise me here. simple

git clone https://github.com/xxx/yyy.git 

( don't want try fear of messing local repo )

you can add additional remote branch repo:

git remote add <yyy> https://github.com/xxx/yyy.git

once that's done, can pull directly new remote with:

git pull <yyy> master

this automatically attempt merge code remote repo local repo.