Running code and the integrated terminal

VSCode itself does not know how to run Python code or any other language. VSCode instead uses tools installed on your computer to run programs, e.g., the Python tools you downloaded from https://python.org. So if you want to use VSCode to develop, e.g., Java or Javascript programs, you need to have the necessary tools installed on your system.

VSCode will automatically find language tools on your file system if they are installed in a “standard” location.

Running code

There are three ways to run a program file:

1. Select the Run menu at the top, then Start Debugging
   • If necessary, select the Python Debugger popup, and select default options of subsequent pop-ups until you see the program run in the interactive Terminal at the bottom.
   • We will discuss the difference between Start Debugging and Run Without Debugging in the future.
2. In the editor window, Right-click anywhere in the code to open the context menu, then select Run Python > Run Python File in Terminal.
3. Press the F5 hotkey to start debugging.

By default, VSCode will run the file in the active editor. Alternately, you can right-click a different file in the Explorer and run it.

Exercise

1. Create hello.py in the python-test directory if needed and add print("Hello World")
2. Run hello.py using the Run menu
3. Run it using the editor context window
4. Use the F5 key. If your F5 key is missing or hard to work with, use Google to research “how to reassign keyboard shortcuts in VSCode”. Reassigning it to the shortcut Cmd+R or Ctrl+R is a solid option.

The Integrated Terminal

When you ran your hello.py program, you should have seen a flurry of output in the Integrated Terminal window at the bottom. What just happened?

1. VSCode opened a Terminal CLI, like you did in the Launching a Terminal lab, except this one is embedded in VSCode.
2. VSCode issued the CLI command python with your file as an argument.
3. python runs in the Terminal and prints output.

Your Terminal contents will different, however, you should see Hello World in there.

Remember, VSCode doesn’t run Python code itself – it uses the tools installed on your computer to do it.

Important note: The Terminal in VSCode is an embedded version of the Terminal we used in Intro to the CLI. You can use the same CLI commands like cd, ls, mkdir, etc.

You may find it convenient to use this integrated Terminal rather than switching to a separate windows. Or you may prefer to keep them separate. Do what works for you.

You can always open the Terminal in VSCode by clicking the Terminal pane (highlighted red in the figure above), or by selecting the Terminal menu at the top.

Exercise

1. List directory contents in the integrated Terminal using the ls command.
2. Type cd ~ in the integrated Terminal to switch to your home directory. Notice how the Explorer pane does not change. You are only changing the working directory in the Terminal.
3. Run hello.py again using VSCode. What happens in the Terminal?
4. Use the Terminal to navigate to your python-test directory using cd commands.
5. Run the command touch hello2.py. Does it appear in the Explorer pane?
6. Run the command rm hello2.py. What happened? What happened in the Explorer pane?

Knowledge check:

• Question: What is the keyboard shortcut for debugging/running your program?
• Question: How do you open an integrated Terminal without running a Python program?
• Question: How can you print the name of the current working directory in the integrated Terminal?
• Question: If you have a runaway process in the integrated Terminal, how do you cancel/kill it? (The answer is the same as for the regular Terminal.)