reflex-dev/reflex · error · TypeError

f"The radio group component takes in a list, got {items_type

Error message

f"The radio group component takes in a list, got {items_type} instead"

What it means

rx.radio_group(items=...) requires items to be a Python list or a Var whose type is a list. Anything else (a string, tuple, set, dict, or a Var of a non-list type) raises TypeError because the component compiles the list into radio options.

Source

Thrown at packages/reflex-components-radix/src/reflex_components_radix/themes/components/radio_group.py:169

            The created radio group component.

        Raises:
            TypeError: If the type of items is invalid.
        """
        direction = props.pop("direction", "row")
        spacing = props.pop("spacing", "2")
        size = props.pop("size", "2")
        variant = props.pop("variant", "classic")
        color_scheme = props.pop("color_scheme", None)
        default_value = props.pop("default_value", "")

        if not isinstance(items, (list, Var)) or (
            isinstance(items, Var)
            and not types.typehint_issubclass(items._var_type, list)
        ):
            items_type = type(items) if not isinstance(items, Var) else items._var_type
            msg = f"The radio group component takes in a list, got {items_type} instead"
            raise TypeError(msg)

        default_value = LiteralVar.create(default_value)

        # convert only non-strings to json(JSON.stringify) so quotes are not rendered
        # for string literal types.
        if isinstance(default_value, str) or (
            isinstance(default_value, Var) and default_value._var_type is str
        ):
            default_value = LiteralVar.create(default_value)
        else:
            default_value = LiteralVar.create(default_value).to_string()

        def radio_group_item(value: Var) -> Component:
            item_value = cond(
                value.js_type() == "string",
                value,
                value.to_string(),
            ).to(StringVar)

View on GitHub (pinned to 45b8ed5ab7)

Solutions

1. Pass a list literal: rx.radio_group(items=['a','b','c'])
2. Type state fields as lists: options: list[str] = ['a','b']
3. Convert tuples/sets: rx.radio_group(items=list(my_tuple))

Example fix

# before
rx.radio_group(items=('low','medium','high'))
# after
rx.radio_group(items=['low','medium','high'])

items = list(items) if isinstance(items, tuple) else items
assert isinstance(items, list) or (isinstance(items, Var) and issubclass(items._var_type, list))
rx.radio_group(items=items)

def valid_items(v) -> bool:
    from reflex.vars import Var
    return isinstance(v, list) or (isinstance(v, Var) and issubclass(v._var_type, list))

When it happens

Trigger: rx.radio_group(items='a,b,c'), items=('a','b') (tuple), items={'a','b'} (set), or items=State.names where names: str.

Common situations: Passing a comma-separated string from a config; storing options as a tuple/JSON string in state; forgetting to json.loads() API data before assignment.

Related errors

• Only Radix TextFieldRoot and DebounceInput are allowed as ch
• Invalid data type {type(data)} for download. Use `str` or `b
• Unsupported Operand type(s) for {operator}: {', '.join(t.__n
• Expected a mapping type or a dataclass, got {_var_value!r} o
• Color must be a string or a Var

AI-assisted analysis of reflex-dev/reflex@45b8ed5ab7 (2026-08-28). Data as JSON: /api/errors/d0fa95434f81a8ab. Report an issue: GitHub.