| 26 | |
| 27 | |
| 28 | class LazyChoices(argparse.Action, Generic[T]): |
| 29 | def __init__( |
| 30 | self, |
| 31 | *args, |
| 32 | getter: Callable[[], Iterable[T]], |
| 33 | help_formatter: Optional[Callable[[T, bool], str]] = None, |
| 34 | sort: bool = False, |
| 35 | cache: bool = True, |
| 36 | isolation_mode: bool = False, |
| 37 | **kwargs |
| 38 | ) -> None: |
| 39 | self.getter = getter |
| 40 | self.help_formatter = help_formatter |
| 41 | self.sort = sort |
| 42 | self.cache = cache |
| 43 | self.isolation_mode = isolation_mode |
| 44 | self._help: Optional[str] = None |
| 45 | self._obj: Optional[Iterable[T]] = None |
| 46 | super().__init__(*args, **kwargs) |
| 47 | self.choices = self |
| 48 | |
| 49 | def load(self) -> T: |
| 50 | if self._obj is None or not self.cache: |
| 51 | self._obj = self.getter() |
| 52 | |
| 53 | assert self._obj is not None |
| 54 | return self._obj |
| 55 | |
| 56 | @property |
| 57 | def help(self) -> str: |
| 58 | if self._help is None and self.help_formatter is not None: |
| 59 | self._help = self.help_formatter( |
| 60 | self.load(), |
| 61 | isolation_mode=self.isolation_mode |
| 62 | ) |
| 63 | return self._help |
| 64 | |
| 65 | @help.setter |
| 66 | def help(self, value: Any) -> None: |
| 67 | self._help = value |
| 68 | |
| 69 | def __contains__(self, item: Any) -> bool: |
| 70 | return item in self.load() |
| 71 | |
| 72 | def __iter__(self) -> Iterator[T]: |
| 73 | if self.sort: |
| 74 | return iter(sorted(self.load())) |
| 75 | else: |
| 76 | return iter(self.load()) |
| 77 | |
| 78 | def __call__(self, parser, namespace, values, option_string=None): |
| 79 | setattr(namespace, self.dest, values) |