<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def shell_command():
 """Runs an interactive Python shell in the context of a given Flask application. The application will populate the default namespace of this shell according to its configuration. This is useful for executing small snippets of management code without having to manually configure the application. """

    from flask.globals import _app_ctx_stack
    from ptpython.repl import embed

    app = _app_ctx_stack.top.app
    ctx = {}

    # Support the regular Python interpreter startup script if someone
    # is using it.
    startup = os.environ.get('PYTHONSTARTUP')
    if startup and os.path.isfile(startup):
        with open(startup, 'r') as f:
            eval(compile(f.read(), startup, 'exec'), ctx)

    ctx.update(app.make_shell_context())

    embed(globals=ctx)