Source code for

Additional "types" to handle common CLI situations.

.. autoclass:: RegexType

import argparse
import re

from import ArgumentType

[docs]class RegexType(ArgumentType): """ Factory for validating string options against a regular expression. Instances of RegexType are typically passed as type= arguments to the ArgumentParser add_argument() method or pyApp argument decorator. :param regex: Regular expression string (or pre-compiled expression) :param message: Optional message if validation fails, defaults to a simple fallback. Example of use:: @app.command @argument("--alpha", type=RegexType(r"[a-z]+")) def my_command(args: Namespace): print(args.option) @app.command def my_command(*, alpha: RegexType(r"[a-z]+")): print(alpha) From CLI:: > my_app m_command --alpha abc abc .. versionadded:: 4.2 """ def __init__(self, regex, message: str = None): self._re = re.compile(regex) self._message = message or f"Value does not match {self._re.pattern!r}" def __call__(self, string) -> str: if not self._re.match(string): raise argparse.ArgumentTypeError(self._message) return string