Recipes & Tips

1. inheritance / root exception

# intermediate class to centrally control the default behaviour
class BaseError(Error):  # <-- inherit from this in your code (not directly from ``izulu``)
    __toggles__ = Toggles.None


class MyRealError(BaseError):
    __template__ = "Having count={count} for owner={owner}"
    owner: str
    count: int

2. factories

TODO: self=True / self.as_kwargs() (as_dict forbidden? - recursion)

• stdlib factories

from uuid import uuid4

class MyError(Error):
    id: datetime = factory(uuid4)
    timestamp: datetime = factory(datetime.now)

• lambdas

class MyError(Error):
    timestamp: datetime = factory(lambda: datetime.now().isoformat())

• function

from random import randint

def flip_coin():
    return "TAILS" if randint(0, 100) % 2 else "HEADS

class MyError(Error):
    coin: str = factory(flip_coin)

• method

class MyError(Error):
    __template__ = "Having count={count} for owner={owner}"
    owner: str
    count: int

    def __make_duration(self) -> timedelta:
        kwargs = self.as_kwargs()
        return self.timestamp - kwargs["begin"]

    timestamp: datetime = factory(datetime.now)
    duration: timedelta = factory(__make_duration, self=True)


begin = datetime.fromordinal(date.today().toordinal())
e = MyError(count=10, begin=begin)

print(e.begin)
# 2023-09-27 00:00:00
print(e.duration)
# 18:45:44.502490
print(e.timestamp)
# 2023-09-27 18:45:44.502490

3. handling errors in presentation layers / APIs

err = Error()
view = RespModel(error=err.as_dict(wide=True)


class MyRealError(BaseError):
    __template__ = "Having count={count} for owner={owner}"
    owner: str
    count: int

Additional examples

TBD