Create a tuple from a list, set, or tuple. Create a fixed-type tuple with Traits: ``t = Tuple(Int(), Str(), CStr())`` would be length 3, with Int,Str,CStr for each element. If only one arg is given and it is not a Trait, it is taken as default_value:
(self, *traits: t.Any, **kwargs: t.Any)
| 3732 | _cast_types = (list,) |
| 3733 | |
| 3734 | def __init__(self, *traits: t.Any, **kwargs: t.Any) -> None: |
| 3735 | """Create a tuple from a list, set, or tuple. |
| 3736 | |
| 3737 | Create a fixed-type tuple with Traits: |
| 3738 | |
| 3739 | ``t = Tuple(Int(), Str(), CStr())`` |
| 3740 | |
| 3741 | would be length 3, with Int,Str,CStr for each element. |
| 3742 | |
| 3743 | If only one arg is given and it is not a Trait, it is taken as |
| 3744 | default_value: |
| 3745 | |
| 3746 | ``t = Tuple((1, 2, 3))`` |
| 3747 | |
| 3748 | Otherwise, ``default_value`` *must* be specified by keyword. |
| 3749 | |
| 3750 | Parameters |
| 3751 | ---------- |
| 3752 | *traits : TraitTypes [ optional ] |
| 3753 | the types for restricting the contents of the Tuple. If unspecified, |
| 3754 | types are not checked. If specified, then each positional argument |
| 3755 | corresponds to an element of the tuple. Tuples defined with traits |
| 3756 | are of fixed length. |
| 3757 | default_value : SequenceType [ optional ] |
| 3758 | The default value for the Tuple. Must be list/tuple/set, and |
| 3759 | will be cast to a tuple. If ``traits`` are specified, |
| 3760 | ``default_value`` must conform to the shape and type they specify. |
| 3761 | **kwargs |
| 3762 | Other kwargs passed to `Container` |
| 3763 | """ |
| 3764 | default_value = kwargs.pop("default_value", Undefined) |
| 3765 | # allow Tuple((values,)): |
| 3766 | if len(traits) == 1 and default_value is Undefined and not is_trait(traits[0]): |
| 3767 | default_value = traits[0] |
| 3768 | traits = () |
| 3769 | |
| 3770 | if default_value is None and not kwargs.get("allow_none", False): |
| 3771 | # improve backward-compatibility for possible subclasses |
| 3772 | # specifying default_value=None as default, |
| 3773 | # keeping 'unspecified' behavior (i.e. empty container) |
| 3774 | warn( |
| 3775 | f"Specifying {self.__class__.__name__}(default_value=None)" |
| 3776 | " for no default is deprecated in traitlets 5.0.5." |
| 3777 | " Use default_value=Undefined", |
| 3778 | DeprecationWarning, |
| 3779 | stacklevel=2, |
| 3780 | ) |
| 3781 | default_value = Undefined |
| 3782 | |
| 3783 | if default_value is Undefined: |
| 3784 | args: t.Any = () |
| 3785 | elif default_value is None: |
| 3786 | # default_value back on kwargs for super() to handle |
| 3787 | args = () |
| 3788 | kwargs["default_value"] = None |
| 3789 | elif isinstance(default_value, self._valid_defaults): |
| 3790 | args = (default_value,) |
| 3791 | else: |