o 诪g@sZdZddlZddlmZddlmZmZmZmZgdZ ddZ edfd d Z d d Z dS) z Commonly useful converters. N)_AnnotationExtractor)NOTHING ConverterFactorypipe)default_if_noneoptionalrto_boolcsttr fdd}nfdd}t}|}|r$tj||jd<|}|r2tj||jd<ttr>t|dddS|S)a_ A converter that allows an attribute to be optional. An optional attribute is one which can be set to `None`. Type annotations will be inferred from the wrapped converter's, if it has any. Args: converter (typing.Callable): the converter that is used for non-`None` values. .. versionadded:: 17.1.0 cs|durdS|||SN)valinstfield converterr K/var/www/html/chatdoc2/venv/lib/python3.10/site-packages/attr/converters.pyoptional_converter&s z$optional..optional_convertercs|durdS|Sr r r rr rr-sr returnT) takes_self takes_field) isinstancerrget_first_param_typetypingOptional__annotations__get_return_type)rrxtrtrtr rrr s   r cstur|durd}t|tur|durd}t||dur$t|ttr:jr2d}t|fdd}|Sfdd}|S)a A converter that allows to replace `None` values by *default* or the result of *factory*. Args: default: Value to be used if `None` is passed. Passing an instance of `attrs.Factory` is supported, however the ``takes_self`` option is *not*. factory (typing.Callable): A callable that takes no parameters whose result is used if `None` is passed. Raises: TypeError: If **neither** *default* or *factory* is passed. TypeError: If **both** *default* and *factory* are passed. ValueError: If an instance of `attrs.Factory` is passed with ``takes_self=True``. .. versionadded:: 18.2.0 Nz(Must pass either `default` or `factory`.z5Must pass either `default` or `factory` but not both.z1`takes_self` is not supported by default_if_none.cs|dur|SSr )factoryrdefaultr rdefault_if_none_converterlsz2default_if_none..default_if_none_convertercs|dur|SSr r rr"r rr$ts)r TypeErrorrrr ValueError)r#r!msgr$r r"rrBs    rcCs<t|tr |}|dvrdS|dvrdSd|}t|)a Convert "boolean" strings (for example, from environment variables) to real booleans. Values mapping to `True`: - ``True`` - ``"true"`` / ``"t"`` - ``"yes"`` / ``"y"`` - ``"on"`` - ``"1"`` - ``1`` Values mapping to `False`: - ``False`` - ``"false"`` / ``"f"`` - ``"no"`` / ``"n"`` - ``"off"`` - ``"0"`` - ``0`` Raises: ValueError: For any other value. .. versionadded:: 21.3.0 )Ttrueryesyon1rT)Ffalsefnonoff0rFzCannot convert value to bool: )rstrlowerr&)r r'r r rr }s  r ) __doc__r_compatr_makerrrr__all__r rr r r r rs - ;