Argument Parser

Overview

The interface for pydantic-argparse is the custom typed ArgumentParser class, which provides declarative, typed argument parsing.

This ArgumentParser class presents a very similar interface to the python standard library argparse.ArgumentParser, in an attempt to provide as close to a drop-in-replacement as possible.

Parser Instantiation

To create an instance of the ArgumentParser:

parser = pydantic_argparse.ArgumentParser(
    model=Arguments,
    prog="Program Name",
    description="Program Description",
    version="1.2.3",
    epilog="Program Epilog",
    add_help=True,
    exit_on_error=True,
)

Required Parameters

The required parameters for the ArgumentParser are outlined below:

• model (Type[pydantic.BaseModel]): The model that defines the command-line arguments

Optional Parameters

The optional parameters for the ArgumentParser are outlined below:

• prog (Optional[str]): The program name that appears in the help message
• description (Optional[str]): The program description that appears in the help message
• version (Optional[str]): The program version that appears in the help message
• epilog (Optional[str]): The program epilog that appears in the help message
• add_help (bool): Whether to add the -h / --help help message action
• exit_on_error (bool): Whether to exit, or raise an ArgumentError upon an error

Argument Parsing

To parse command-line arguments into the model using the ArgumentParser:

args = parser.parse_typed_args()

Info

The ArgumentParser is generic over its pydantic model. This means that the parsed args object is type-hinted as an instance of its model.

Optional Parameters

The optional parameters for the parse_typed_args method are outlined below:

• args (Optional[List[str]]): Optional list of arguments to parse instead of sys.argv