bagof.converters.collections

Converters for collection types (list, tuple, dict, etc.).

Classes

ToIterable

ToIterable(hint: Any = UNSET, compose: bool = False)

Bases: Converter[ITERABLE, Any]

Converter for abc.Iterable.

Methods:

like

like(__reentrant: tuple = ()) -> Any

Return the input hint for this converter.

call

__call__(value: Any) -> ITERABLE

Convert the value to an iterable, converting each element.

ToSequence

ToSequence(hint: Any = UNSET, compose: bool = False)

Bases: Converter[SEQUENCE, Any]

Converter for abc.Sequence.

Methods:

like

like(__reentrant: tuple = ()) -> Any

Return the input hint for this converter.

call

__call__(value: Any) -> SEQUENCE

Convert the value to a sequence, converting each element.

ToSet

ToSet(hint: Any = UNSET, compose: bool = False)

Bases: ToIterable

Converter for abc.Set.

Sets convert element-wise like any other iterable.

Note

The only difference from ToIterable is the concrete fallback, so that an abstract Set[int] hint still produces a real container (frozenset, since abc.Set is immutable) rather than a bare iterator.

ToMutableSet

ToMutableSet(hint: Any = UNSET, compose: bool = False)

Bases: ToSet

Converter for abc.MutableSet.

ToMapping

ToMapping(hint: Any = UNSET, compose: bool = False)

Bases: Converter[MAPPING, Any]

Converter for abc.Mapping.

Methods:

like

like(__reentrant: tuple = ()) -> Any

Return the input hint for this converter.

call

__call__(value: Any) -> MAPPING

Convert the value to a mapping, converting each key and value.

ToTuple

ToTuple(hint: Any = UNSET, compose: bool = False)

Bases: Converter[TUPLE, Any]

Converter for tuple.

Methods:

like

like(__reentrant: tuple = ()) -> Any

Return the input hint for this converter.

call

__call__(value: Any) -> TUPLE

Convert the value to a tuple, converting each element.

ToNamedTuple

ToNamedTuple(hint: Any = UNSET, compose: bool = False)

Bases: Converter[TUPLE, Any]

Converter for NamedTuple subclasses.

Accepts a mapping keyed by field name, or any sequence in field order, and converts each field through its declared type.

Note

A NamedTuple is a plain tuple subclass at runtime, so it cannot be a registry key of its own; ToTuple recognises one and delegates here.

Example

>>> import typing_extensions as tx
>>> from bagof.converters import get_converter
>>> class Point(tx.NamedTuple):
...     x: int
...     y: int
>>> get_converter(Point)({"x": "1", "y": "2"})
Point(x=1, y=2)
>>> get_converter(Point)(["1", "2"])
Point(x=1, y=2)

Methods:

like

like(__reentrant: tuple = ()) -> Any

Accept an instance, a mapping by field name, or a sequence.

call

__call__(value: Any) -> TUPLE

Convert the value field by field.

ToLength

ToLength(length: int, hint: Any = UNSET, compose: bool = False)

Bases: ToSequence[ITERABLE]

Converter for sequences of a fixed length.

A longer input is truncated to the requested length, and a shorter one is refused. Coercing to a fixed length is a conversion like any other, so the extra items are dropped rather than rejected.

Warning

This is deliberately more permissive than HasLength in bagof-validators, which refuses a mismatch in either direction. Validate first if you need a long sequence to be an error rather than a trim.

Example

>>> from bagof.converters.collections import ToLength
>>> to_pair = ToLength(2, tx.List[int])
>>> to_pair(["1", "2", "3"])
[1, 2]
>>> to_pair(["1"])
ValueConversionError: Expected sequence of length 2, got 1.

Parameters:

Name	Type	Description	Default
`length`	`int`	The expected length of the sequence.	required
`hint`	`Any`	The type hint to convert to.	`UNSET`
`compose`	`bool`	Whether to compose this converter with others, when they are found in `Annotated` metadata.	`False`

Methods:

call

__call__(value: Any) -> ITERABLE

Convert the value to a sequence, trimmed to the length.