At what stage of execution does the Python interpreter create the constructor object — before compiling the source code or during its execution?

In Python, a constructor object (for example, a class) is created at runtime, not at compile time of the source code. When the interpreter runs, it first compiles the source code into bytecode, but class objects are only created when execution reaches the class definition. This means that a class is a first-class object that is created dynamically during execution.