Check if code is running in GUI

Tioz · October 26, 2020, 8:56am

Hi, is there any way “smart” way of checking if the current nengo .py script is being run in the GUI or not?
I’ve looked through the GUI source code but don’t see an obvious way to do this.

arvoelke · October 26, 2020, 11:54am

I’m not sure if there’s a supported way of doing this, but an unsupported way would be to check:

__name__ == 'builtins'

I’m not sure how robust this is, but I tested it out on nengo-gui==0.4.6 and this is True if the current script is being run in the GUI, and False if being run as a python script from the command line.

travis.dewolf · October 26, 2020, 2:19pm

I’ve also used:

from nengo.simulator import Simulator as NengoSimulator
if nengo.Simulator is not NengoSimulator:
    ...
elif __name__ == "__main__":
    ...

tcstewar · October 26, 2020, 4:59pm

Here’s yet another way:

if '__page__' in locals():

Here’s the part of the nengo_gui code which initializes locals when executing the code

github.com

nengo/nengo-gui/blob/master/nengo_gui/page.py#L215


    uid = self.get_uid(component)
    component.attach(self, self.config[component], uid=uid)
    self.components.append(component)

def execute(self, code):
    """Run the given code to generate self.model and self.locals.

    The code will be stored in self.code, any output to stdout will
    be a string as self.stdout, and any error will be in self.error.
    """
    code_locals = {}
    code_locals['nengo_gui'] = nengo_gui
    code_locals['__file__'] = self.filename
    code_locals['__page__'] = self

    self.code = code
    self.error = None
    self.stdout = ''

    exec_env = nengo_gui.exec_env.ExecutionEnvironment(self.filename)
    try:

We set the __file__ variable here, and we also create this other variable __page__ which refers to the nengo_gui.page.Page object that’s running that page.

It’d still be nicer to have a better way to do that… something like a nengo_gui.is_running_in_ui flag that could be checked… But we don’t have anything like that yet.