Missing Type Annotations

[FoamyGuy]

There are missing type annotations for some functions in this library.

The typing module does not exist on CircuitPython devices so the import needs to be wrapped in try/except to catch the error for missing import. There is an example of how that is done here:

try:
    from typing import List, Tuple
except ImportError:
    pass

Once imported the typing annotations for the argument type(s), and return type(s) can be added to the function signature. Here is an example of a function that has had this done already:

def wrap_text_to_pixels(
    string: str, max_width: int, font=None, indent0: str = "", indent1: str = ""
) -> List[str]:

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If you are attempting to resolve this issue and need help, you can post a comment on this issue and tag both @FoamyGuy and @kattni or reach out to us on Discord: https://adafru.it/discord in the #circuitpython-dev channel.

The following locations are reported by mypy to be missing type annotations:

• adafruit_displayio_ssd1305.py:68

[tcfranks]

@FoamyGuy , @kattni , or @tekktrik

The init on this part is def init(self, bus, **kwargs) -> None

bus can be spi or i2c: in the past I've used displayio.I2C or displayio.Fourwire , so does this really make any difference here? or is there a better way to annotate 'bus'?

[FoamyGuy]

@tcfranks

Looking into the code it looks like bus gets passed along to the displayio.Display() constructor which in the docs here: https://docs.circuitpython.org/en/latest/shared-bindings/displayio/index.html?highlight=displayio.Display is typed as displayio._DisplayBus so I think it could match that here, though I'm unsure if the leading underscore means we shouldn't actually use that for the typing information in the library.

Another option, as you noted in the discord is using something like Union[I2C, FourWire] which I also think is good. Perhaps even better since it doesn't use anything "private" I would probably lean toward doing it this way to start and we can get input from others.

Perhaps there should be something in circuitpython_typing for this ultimately as well.

[tekktrik]

We could probably even have it directly in the Blinka displayio library. The only example I see is a FourWire, are there any I2C ones as well?

[tcfranks]

We could probably even have it directly in the Blinka displayio library. The only example I see is a FourWire, are there any I2C ones as well?

it's in sampletest as well, just commented out:

Use for SPI

spi = board.SPI()
oled_cs = board.D5
oled_dc = board.D6
display_bus = displayio.FourWire(
spi, command=oled_dc, chip_select=oled_cs, baudrate=1000000, reset=oled_reset
)

Use for I2C
i2c = board.I2C()
display_bus = displayio.I2CDisplay(i2c, device_address=0x3c, reset=oled_reset)

[tcfranks]

sorry - had issues with the hash sign in comment