virtualenv test_env                         # Creates a folder, containing a virtual environment
source test_env/bin/activate                # Activates that environment
source test_env/bin/activate.fish           # Activates that environment for fish shell
which python3                               # Prints location of Python executable (can also test which pip3)
pip3 list                                   # List installed packages
pip3 install <PACKAGE-NAME>                 # Install package
pip3 freeze --local > requirements.txt      # Writes all installed packages to .txt file. With that, environment can be easily recreated
deactivate                                  # Deactivate environment

# Installs ipykernel, so that 'test' kernel jupyter notebook can use kernel 'test'
# With that, jupyter notebook uses the libraries from the activated environment (instead of the globally installed libraries)
python3 -m ipykernel install --user --name=test

virtualenv -p /usr/bin/python3 test_env     # Optional: Use certain python version
pip3 install -r requirements.txt            #  # Uses requirements.txt inside environment folder to install packages
deactivate

git init                         # Initialize a git repository
git status                       # Check staged files
git add <file>                   # Add changed file to stage
git commit -m "<comment>"        # Add commit
git pull                         # Pull repository branch
git push                         # Push current staged files

git config --global user.name "First last"          # Set user name
git config --global user.email "email adress"       # Set user email
git config --list                                   # Lists configuration values

git help config                   # Shows help for a command
git config --help                 # Same as above

git init                # Run this from within the project folder to start tracking
ls -la                  # Shows additional .git directory, contains everything that is
                        # related to the git repo -> If one wants to stop tracking that
                        # project with git, only delete that repo with rm -rf .git
git status              # Shows status of tracking

touch .gitignore        # .gitignore file contains private file that shouldn't be tracked
                        # wildcards can be used, e.g. *.pyc, folders can also be added

git add <file>                                # Adds file to staging area
git *                                         # Adds everything to the staging area
git add -A                                    # Adds everything to the staging area
git reset <file>                              # Removes file from staging area
git reset                                     # Removes everything from staging area
git commit -m "specify changes to code"       # Commit staged files with a message
git status                                    # Now there are no untracked files, therefore the working directory is clean
git log                                       # Shows commit with its unique hash, author and date

git clone <url> <path_to_clone>               # General cloning command
git clone ../remote_repo.git .                # Clones all files from remote_repo.git dicectory to .

git remote -v                                 # View information about repository

git pull origin master                        # Always pull before push, people could have changed the code in the
                                              # Origin is the name of repository, master is branch we want to push to
git push origin master                        # Pushes local changes to repo, so other people have access to it

git branch <name>                             # Creates branch with the name "name"
git branch <name> <root-branch>               # Creates branch, based on existing branch
git branch                                    # Shows local branches
git branch -a                                 # Shows local and remote branches

git checkout <master>                         # Switch to branch <master>
git pull origin master                        # Get changes
git merge <branch> master                     # Merges <branch> and master
git branch --merged                           # Shows merged branch
git push origin master
git branch -d <branch>                        # Branch can now be deleted

git stash 
git fetch origin main:main
git rebase main
# Force with lease prevents pushing changes since the fetch, if someone else has pushed since then
git push --force-with-lease origin feat/test-branch    
git stash pop

ln -s {source-filename} {symbolic-filename}             # Soft link named symbolic-filename, refering to the symbolic filepath
# Note that source-filename can also be a directory, e.g. such as
ln -s /home/test/http/users/manuel/ /app/
# Soft links serve as a reference to another file or directory. Hard links refer to the actual location of physical data.

# Creates HTTP server that can be accessed in the same network (by calling IP address and port in browser, e.g. 127.0.0.1:8000)
# With that, files between computers in the same network can be exchanged
python3 -m http.server

# Prints information on access to internet. 1 is 'something historical' (can be ignored),
# 2 is ethernet cable, 3 (wl) is wifi: inet xxx.xxx.xxx.xx shows the IP address,
# 4 is internet access for the docker container
ip address