literal

Parses Literal Pydantic Fields to Command-Line Arguments.

The literal module contains the should_parse function, which checks whether this module should be used to parse the field, as well as the parse_field function, which parses literal pydantic model fields to ArgumentParser command-line arguments.

should_parse(field)

Checks whether the field should be parsed as a literal.

Parameters:

Name	Type	Description	Default
field	pydantic.fields.ModelField	Field to check.	required

Returns:

Type	Description
bool	Whether the field should be parsed as a literal.

Source code in pydantic_argparse/parsers/literal.py

def should_parse(field: pydantic.fields.ModelField) -> bool:
    """Checks whether the field should be parsed as a `literal`.

    Args:
        field (pydantic.fields.ModelField): Field to check.

    Returns:
        bool: Whether the field should be parsed as a `literal`.
    """
    # Check and Return
    return utils.types.is_field_a(field, Literal)

parse_field(parser, field)

Adds enum pydantic field to argument parser.

Parameters:

Name	Type	Description	Default
parser	argparse.ArgumentParser	Argument parser to add to.	required
field	pydantic.fields.ModelField	Field to be added to parser.	required

Returns:

Type	Description
Optional[utils.pydantic.PydanticValidator]	Possible validator method.

Source code in pydantic_argparse/parsers/literal.py

def parse_field(
    parser: argparse.ArgumentParser,
    field: pydantic.fields.ModelField,
) -> Optional[utils.pydantic.PydanticValidator]:
    """Adds enum pydantic field to argument parser.

    Args:
        parser (argparse.ArgumentParser): Argument parser to add to.
        field (pydantic.fields.ModelField): Field to be added to parser.

    Returns:
        Optional[utils.pydantic.PydanticValidator]: Possible validator method.
    """
    # Extract Choices
    choices = get_args(field.outer_type_)

    # Compute Argument Intrinsics
    is_flag = len(choices) == 1 and not bool(field.required)
    is_inverted = is_flag and field.get_default() is not None and field.allow_none

    # Determine Argument Properties
    metavar = f"{{{', '.join(str(c) for c in choices)}}}"
    action = argparse._StoreConstAction if is_flag else argparse._StoreAction
    const = {} if not is_flag else {"const": None} if is_inverted else {"const": choices[0]}

    # Add Literal Field
    parser.add_argument(
        utils.arguments.name(field, is_inverted),
        action=action,
        help=utils.arguments.description(field),
        dest=field.alias,
        metavar=metavar,
        required=bool(field.required),
        **const,  # type: ignore[arg-type]
    )

    # Construct String Representation Mapping of Choices
    # This allows us O(1) parsing of choices from strings
    mapping = {str(choice): choice for choice in choices}

    # Construct and Return Validator
    return utils.pydantic.as_validator(field, lambda v: mapping[v])