61 lines
1.9 KiB
Python
61 lines
1.9 KiB
Python
|
"""Preconfigured converters for pyyaml."""
|
||
|
|
from datetime import date, datetime
|
||
|
|
from typing import Any, Type, TypeVar, Union
|
||
|
|
|
||
|
|
from yaml import safe_dump, safe_load
|
||
|
|
|
||
|
|
from cattrs._compat import FrozenSetSubscriptable
|
||
|
|
|
||
|
|
from ..converters import BaseConverter, Converter
|
||
|
|
from ..strategies import configure_union_passthrough
|
||
|
|
from . import validate_datetime
|
||
|
|
|
||
|
|
T = TypeVar("T")
|
||
|
|
|
||
|
|
|
||
|
|
def validate_date(v, _):
|
||
|
|
if not isinstance(v, date):
|
||
|
|
raise ValueError(f"Expected date, got {v}")
|
||
|
|
return v
|
||
|
|
|
||
|
|
|
||
|
|
class PyyamlConverter(Converter):
|
||
|
|
def dumps(self, obj: Any, unstructure_as: Any = None, **kwargs: Any) -> str:
|
||
|
|
return safe_dump(self.unstructure(obj, unstructure_as=unstructure_as), **kwargs)
|
||
|
|
|
||
|
|
def loads(self, data: str, cl: Type[T]) -> T:
|
||
|
|
return self.structure(safe_load(data), cl)
|
||
|
|
|
||
|
|
|
||
|
|
def configure_converter(converter: BaseConverter):
|
||
|
|
"""
|
||
|
|
Configure the converter for use with the pyyaml library.
|
||
|
|
|
||
|
|
* frozensets are serialized as lists
|
||
|
|
* string enums are converted into strings explicitly
|
||
|
|
* datetimes and dates are validated
|
||
|
|
"""
|
||
|
|
converter.register_unstructure_hook(
|
||
|
|
str, lambda v: v if v.__class__ is str else v.value
|
||
|
|
)
|
||
|
|
|
||
|
|
# datetime inherits from date, so identity unstructure hook used
|
||
|
|
# here to prevent the date unstructure hook running.
|
||
|
|
converter.register_unstructure_hook(datetime, lambda v: v)
|
||
|
|
converter.register_structure_hook(datetime, validate_datetime)
|
||
|
|
converter.register_structure_hook(date, validate_date)
|
||
|
|
configure_union_passthrough(
|
||
|
|
Union[str, bool, int, float, None, bytes, datetime, date], converter
|
||
|
|
)
|
||
|
|
|
||
|
|
|
||
|
|
def make_converter(*args: Any, **kwargs: Any) -> PyyamlConverter:
|
||
|
|
kwargs["unstruct_collection_overrides"] = {
|
||
|
|
FrozenSetSubscriptable: list,
|
||
|
|
**kwargs.get("unstruct_collection_overrides", {}),
|
||
|
|
}
|
||
|
|
res = PyyamlConverter(*args, **kwargs)
|
||
|
|
configure_converter(res)
|
||
|
|
|
||
|
|
return res
|