TypeError: 'slice' object isn't callable

[lbuque]

micropython 1.20.0
board: esp32 + 2m psram + 8m flash

I am using uasyncio to make a ui, when _BtnB_wasClicked_event is triggered, it will be passed to App's _keycode_dpad_down_event_handler.

However, sometimes it works fine, and sometimes the following exception occurs:

[peterhinch]

I have moved this to discussions because you have provided no evidence of e MicroPython bug. To enable us to find the bug in the code you'll need to provide more information including the traceback and the code where the error occurs.

[sosi-deadeye]

Without the line number from the traceback it's hard to find the bug.

You're calling somewhere a slice object and those are not callable.
You can't create a slice object directly in Micropython, but the __getitem__ method of a class gets a slice object if a range is selected.

Example:

class Foo:
    def __getitem__(self, key):
        print(key)

# not a slice object
# Foo()[1]
# 1

# slice object
Foo()[:]
# slice(None, None, None)

# slice object
Foo()[0:]
# slice(0, None, None)


# slice object
Foo()[0:10]
# slice(0, 10, None)

# slice object
Foo()[0:10:2]
# slice(0, 10, 2)

Somewhere in your code, a name is assigned to a slice object. Later it's called, which raises a TypeError.

[lbuque]

I made the following modifications, which seem to avoid the exception: