How does the Python interpreter execute scripts entered in the command line?

When a Python script is run from the command line, the interpreter performs the following steps:

1. Reads the script file or the code string passed via the command line.
2. Compiles the source code into bytecode — an intermediate representation that executes more efficiently.
3. Runs the Python Virtual Machine (PVM), which interprets the bytecode and executes the instructions.

For example, the command:

python -c "print('Hello, world!')"

causes the interpreter to execute the code string passed with the -c parameter. The interpreter compiles this string and immediately executes it, outputting the result to the console.