Scipy Trait Types
Trait types for NumPy, SciPy and friends
Provide a reference implementation of trait types for common data structures used in the scipy stack such as
which are out of the scope of the main traitlets project but are a common requirement to build applications with traitlets in combination with the scipy stack.
Another goal is to create adequate serialization and deserialization routines
for these trait types to be used with the ipywidgets
from_json). These could also return a list of binary
buffers as allowed by the current messaging protocol.
Make sure you have pip installed and run:
pip install traittypes
conda install -c conda-forge traittypes
traittypes extends the
traitlets library with an implementation of trait types for numpy arrays, pandas dataframes, pandas series, xarray datasets and xarray dataarrays.
traittypesworks around some limitations with numpy array comparison to only trigger change events when necessary.
traittypesalso extends the traitlets API for adding custom validators to constained proposed values for the attribute.
For a general introduction to
traitlets, check out the traitlets documentation.
Example usage with a custom validator
from traitlets import HasTraits, TraitError from traittypes import Array def shape(*dimensions): def validator(trait, value): if value.shape != dimensions: raise TraitError('Expected an of shape %s and got and array with shape %s' % (dimensions, value.shape)) else: return value return validator class Foo(HasTraits): bar = Array(np.identity(2)).valid(shape(2, 2)) foo = Foo() foo.bar = [1, 2] # Should raise a TraitError