问TypeError：“coroutine”对象不可订阅？

EN

I'm working on a project where I get device data from ibeacon bluetooth devices. Normally I can have all Mac addresses and device local_names. But when I want to change the code a little bit I can't get the Mac addresses

devices = await BleakScanner.discover(return_adv=True)

for d, a in devices.values():
    print()
    print(d)                    # beacon names are POI
    print("-" * len(str(d)))
    print(a)

FF:CC:DD:KK:8A:01: POI
----------------------
AdvertisementData(local_name='POI', manufacturer_data={76: b'\x02\x15\x85x\xd2\x85\xfd\x1fO{6\xf2\x1b2\x97\xd6\xf0\xe3\x00\x01\x00$\xbd'}, service_data={'0000180a-0000-1000-8000-00805f9b555': b'\x05\x01\xc2c'}, rssi=-88)

    print(f"Mac Adress : {macadress[0]}")// => problem line 
    print(f"Local Name : {name}")
    print(f"UUID     : {uuid}")
    print(f"Major    : {ibeacon.major}")
    print(f"Minor    : {ibeacon.minor}")
    print(f"TX power : {ibeacon.power} dBm")
    print(f"RSSI     : {device.rssi} dBm")
    print(47 * "-")
except KeyError:
    # Apple company ID (0x004c) not found
    pass
except ConstError:
    # No iBeacon (type 0x02 and length 0x15)
    pass

while True:
    await scanner.start()
    await asyncio.sleep(1.0)
    await scanner.stop()

result = TypeError: 'coroutine' object is not subscriptable

Executing Code

import asyncio

from bleak import BleakScanner


async def main():
    print("scanning for 5 seconds, please wait...")

    devices = await BleakScanner.discover(return_adv=True)
    
    for d, a in devices.values():
        print()
        print(d)                    # beacon names are POI
        print("-" * len(str(d)))
        print(a)
    
    

if __name__ == "__main__":
    asyncio.run(main())

Here we can get mac addresses 

but there isnt 

import asyncio
from uuid import UUID

from construct import Array, Byte, Const, Int8sl, Int16ub, Struct
from construct.core import ConstError

from bleak import BleakScanner
from bleak.backends.device import BLEDevice
from bleak.backends.scanner import AdvertisementData

ibeacon_format = Struct(
    "type_length" / Const(b"\x02\x15"),
    "uuid" / Array(16, Byte),
    "major" / Int16ub,
    "minor" / Int16ub,
    "power" / Int8sl,
)

def device_found(
    device: BLEDevice, advertisement_data: AdvertisementData
):
    """Decode iBeacon."""
    try:
        macadress = BleakScanner.discover(return_adv=True) // => problem line 
        name = advertisement_data.local_name
        apple_data = advertisement_data.manufacturer_data[0x004C]
        ibeacon = ibeacon_format.parse(apple_data)
        uuid = UUID(bytes=bytes(ibeacon.uuid))

        print(f"Mac Adress : {macadress[0]}")// => problem line 
        print(f"Local Name : {name}")
        print(f"UUID     : {uuid}")
        print(f"Major    : {ibeacon.major}")
        print(f"Minor    : {ibeacon.minor}")
        print(f"TX power : {ibeacon.power} dBm")
        print(f"RSSI     : {device.rssi} dBm")
        print(47 * "-")
    except KeyError:
        # Apple company ID (0x004c) not found
        pass
    except ConstError:
        # No iBeacon (type 0x02 and length 0x15)
        pass



async def main():
    """Scan for devices."""
    scanner = BleakScanner()
    scanner.register_detection_callback(device_found)


    while True:
        await scanner.start()
        await asyncio.sleep(1.0)
        await scanner.stop()
        
asyncio.run(main())