dataclasses

test_global_config.py has a usage example

Hello,
I'm having problems creating a database, mostly due to lack of any examples.
I can create a page just fine, but am having problems with databases.
I think I just get type/format of the title and properties wrong.

Would be great to have an example of how to create a database with a title and a text property.

Thanks for your great work!

It is common to have Union traits of the form Union(None, <something>). As a convenience to developers, and following a similar convention in Python's typing module, we should consider having Optional(<something>) as an alternative way of writing Union(None, <something>).

An alternative would be to make allow_none metadata universally accepted across TraitType instances.

Just fix tests to use Factory instead of old style

Describe the bug
When help text is added to a field that does not have a default value, the help text indicates a default value of None when it should not.

To Reproduce

#!/usr/bin/env python3
# test_simple.py
from dataclasses import dataclass
from simple_parsing import ArgumentParser

@dataclass
class Options:
    list_items: list[str]  # SOMETHING

parser = Argume

https://docs.python.org/3/reference/datamodel.html#object.__bytes__

It seems that the typing module doesn't flatten nested literal type definitions, so the following does not currently work:

SuccessStatus = Literal[200, 201, 204]
ClientError = Literal[404, 401, 403, 409, 400]
ServerError = Literal[500, 504, 503]

@dataclass
class HttpResponse(JsonSchemaMixin):
    status: Literal[SuccessStatus, ClientError, ServerError]
    ...

Mypy fails on desert currently.