docopt-typed 0.1.0

A lightweight helper around docopt-ng adding automatic type conversion

docopt-typed

docopt-typed is a lightweight helper around docopt-ng that keeps the ergonomics of docstrings-as-interfaces while adding automatic type conversion. Annotate your usage text with the familiar <type> markers and receive a ParsedOptions object whose values already match those types.

Features

• Works as a drop-in replacement for docopt while returning the same ParsedOptions object
• Converts values to Python types by reading <type> (or <name:type>) hints in the usage text
• Supports common primitives (int, float, bool, str, path) plus JSON-backed structures, complex numbers, and none/null
• Keeps raw strings when a conversion fails so you can decide how to handle edge cases
• Treats option and positional argument annotations the same, so flags and required arguments can both be typed

Installation

pip install docopt-typed

or

uv add docopt-typed

Usage

Import docopt_typed instead of docopt and describe your CLI exactly as you would with docopt-ng, adding type annotations inside angle brackets. The example below mirrors the runnable block at the bottom of src/docopt_typed/docopt_typed.py and shows both option and positional annotations:

from docopt_typed import docopt_typed

__doc__ = """Usage:
  myprogram.py --speed=<int> INPUT_FILE [options]

Arguments:
  INPUT_FILE <path>       The path to read from

Options:
  -s, --speed=<int>       Speed in mph (integer)
  -v, --verbose=<bool>    Enable verbose logging (true/false) [default: false]
  -n, --name=<str>        Your name [default: Alice]
  -d, --debug             Enable debug mode (no value needed)
"""

args = docopt_typed(__doc__)
print(args.speed, type(args.speed))        # 60 <class 'int'>
print(args.verbose, type(args.verbose))    # True <class 'bool'>
print(args.name, type(args.name))          # Bob <class 'str'>
print(args.debug, type(args.debug))        # True <class 'bool'>
print(args.INPUT_FILE, type(args.INPUT_FILE))  # Positional argument converted to Path

Running the script as python myprogram.py --speed=60 --verbose=true --name=Bob input.txt produces an already-typed result. Positional arguments are annotated by placing the type marker alongside the name (e.g. INPUT_FILE <path> in the Arguments section), while options continue to use the --flag=<type> pattern.

Supported type hints

The converter looks for the <type> token associated with each option or argument name and applies the matching callable:

• int, float, complex
• bool, boolean (accepts true/false, 1/0, yes/no, on/off in any case)
• str, string, text
• json, dict, list (parsed with json.loads)
• bytes (UTF-8 encoding of the provided value)
• path, file, filepath, dir, directory (converted to pathlib.Path)
• none, null (converted to None)

Any pattern that cannot be converted cleanly is left untouched as the original string so you can handle validation yourself.

Attribute access and testing

docopt_typed returns the same ParsedOptions object as docopt-ng, so you can access results via args["--speed"] or args.speed. The accompanying tests in tests/test_docopt.py demonstrate how to supply custom argument lists, assert on types, and verify behavior for short-form flags and various boolean spellings.

Error handling

When a hint is missing, misspelled, or unsupported, the original string is preserved. This mirrors docopt's philosophy of trusting the usage documentation and keeps the wrapper safe as a drop-in replacement.