Source code for argschema.fields.slice

import marshmallow as mm

[docs]class Slice(mm.fields.Str): """Slice is a :class:'marshmallow.fields.Str' field that supports a range or slice argument for selecting some subset of a larger dataset. The syntax is identical to numpy slicing. Examples: "10:20", "40", ":30", "10:2:40" Parameters ---------- kwargs : the same as any :class:`~masrshmallow.fields.Str` receive """ def __init__(self, **kwargs): kwargs['metadata'] = kwargs.get( 'metadata', {'description': 'slice the dataset'}) kwargs['default'] = kwargs.get('default', slice(None)) super(Slice, self).__init__( **kwargs) def _deserialize(self, value, attr, obj, **kwargs): try: args = tuple([int(c) if c else None for c in value.split(':')]) return slice(*args) except: raise mm.ValidationError( '{} is not a properly formatted slice'.format(value))