def schema(self) -> str:
""" PostGres schema string """
schema = []
for field, field_type in self.fields.items():
field_type = guard_generic_alias(field_type)
if field_type in [list, tuple, Sequence, Collection]:
field_type = [typing_get_args(field_type[0])]
dimensions = 0
while isinstance(field_type,
Sequence) and not isinstance(field_type, str):
if len(field_type) > 0:
field_type = field_type[0]
else:
field_type = list
dimensions += 1
if isinstance(field_type, Mapping):
field_type = dict
try:
field_type = self.FIELD_TYPES[field_type.__name__]
except KeyError:
raise TypeError(
f'PostGres does not support type "{field_type}"')
schema.append(f'{field} {field_type}{"[]" * dimensions}')
schema.append(f'PRIMARY KEY({", ".join(self.primary_key)})')
return ', '.join(schema)
def get_args(tp: Type[Any]) -> Tuple[Any, ...]:
"""Get type arguments with all substitutions performed.
For unions, basic simplifications used by Union constructor are performed.
Examples::
get_args(Dict[str, int]) == (str, int)
get_args(int) == ()
get_args(Union[int, Union[T, int], str][int]) == (int, str)
get_args(Union[int, Tuple[T, int]][str]) == (int, Tuple[str, int])
get_args(Callable[[], T][int]) == ([], int)
"""
# the fallback is needed for the same reasons as `get_origin` (see above)
return typing_get_args(tp) or getattr(tp, '__args__',
()) or generic_get_args(tp)