Add Base Class for Handling EnkaNetwork Errors

[luoshuijs]

Our hope is to create a base class that can gracefully catch exceptions thrown from the EnkaNetwork.py module

class EnkaNetworError(Exception):
    """Base class for EnkaNetwork errors."""


class NetworkError(EnkaNetworError):
    """Base class for exceptions due to networking errors."""


class TimedOut(NetworkError):
    """Raised when a request took too long to finish."""


class BadRequest(EnkaNetworError):
    """Raised when EnkaNetwork could not process the request correctly."""


class EnkaValidateFailed(BadRequest):
    """Exception that's raised for when status code 400 occurs."""


...

[luoshuijs]

NetworkError can be from the aiohttp base exception.

try:
    await do_request()
except asyncio.TimeoutError as err:
    # aiohttp.ClientSession throws subclasses of aiohttp.ClientError on connection issues,
    # except for timeouts,
    # where it throws asyncio.TimeoutError.
    raise TimedOut from err
except aiohttp.ClientError as err:
    raise NetworkError from err

We include the class name for easier debugging.
Especially useful if the error.

[luoshuijs]

If the above things are done, developers can better handle exceptions.

client = EnkaNetworkAPI(lang="en")
try:
    # do something, like get uid
    async with client:
        data = await client.fetch_user(uid)
except TimedOut:
    print("Connection timeout, please try again")
except BadRequest as exc:
    print(exc.message)
    # Notify user information that EnkaNetwork could not process the request correctly
except EnkaNetworError as exc:
    sentry.report(exc)
    # Notify developer information that something wrong with EnkaNetwor.py modules

Avoid catching very general exceptions. (PYL-W0703)