dtype

Todo

This section is under construction as of 1.6.1

Much of the details of dtypes are covered in syntax and in numpydantic.dtype , but this section will specifically address how dtypes are handled both generically and by interfaces as we expand custom dtype handling <3.

For details of support and implementation until the docs have time for some love, please see the tests, which are the source of truth for the functionality of the library for now and forever.

Recall the general syntax:

NDArray[Shape, dtype]

These are the docs for what can do in dtype.

Scalar Dtypes

Python builtin types and numpy types should be handled transparently, with some exception for complex numbers and objects (described below).

Numbers

Complex numbers

Todo

Document limitations for complex numbers and strategies for serialization/validation

Datetimes

Todo

Datetimes are supported by every interface except :class:.VideoInterface , with the caveat that HDF5 loses timezone information, and thus all timestamps should be re-encoded to UTC before saving/loading.

More generic datetime support is TODO.

Objects

Todo

Generic objects are supported by all interfaces except :class:.VideoInterface , :class;.HDF5Interface , and :class:.ZarrInterface .

this might be expected, but there is also hope, TODO fill in serialization plans.

Strings

Todo

Strings are supported by all interfaces except :class:.VideoInterface .

TODO is fill in the subtleties of how this works

Generic Dtypes

Todo

For now these are handled as tuples of dtypes, see the source of numpydantic.dtype.Float . They should either be handled as Unions or as a more prescribed meta-type.

For now, use int and float to refer to the general concepts of “any int” or “any float” even if this is a bit mismatched from the numpy usage.

Extended Python Typing Universe

Union Types

Union types can be used as expected.

Union types are tested recursively – if any item within a Union matches the expected dtype at a given level of recursion, the dtype test passes.

class MyModel(BaseModel):
    array: NDArray[Any, int | float]

Compound Dtypes

Todo

Compound dtypes are currently unsupported, though the HDF5 interface supports indexing into compound dtypes as separable dimensions/arrays using the third “field” parameter in hdf5.H5ArrayPath .