Textualize/textual · error · ValueError

Input type must be one of {friendly_list(_RESTRICT_TYPES.key

Error message

Input type must be one of {friendly_list(_RESTRICT_TYPES.keys())}; not {type!r}

What it means

A ValueError raised in Input.__init__ when the type argument is not one of the keys of _RESTRICT_TYPES (typically 'text', 'integer', 'number', 'password' — the exact set depends on the Textual version). Input uses this enum to configure input filtering/validation, so unknown strings are rejected at construction.

Source

Thrown at src/textual/widgets/_input.py:441

        )
        """Set with event names to do input validation on.

        Validation can only be performed on blur, on input changes and on input submission.

        Example:
            This creates an `Input` widget that only gets validated when the value
            is submitted explicitly:

            ```py
            input = Input(validate_on=["submitted"])
            ```
        """
        self._reactive_valid_empty = valid_empty
        self._valid = True

        self.restrict = restrict
        if type not in _RESTRICT_TYPES:
            raise ValueError(
                f"Input type must be one of {friendly_list(_RESTRICT_TYPES.keys())}; not {type!r}"
            )
        self.type = type
        self.max_length = max_length
        if not self.validators:
            from textual.validation import Integer, Number

            if self.type == "integer":
                self.validators.append(Integer())
            elif self.type == "number":
                self.validators.append(Number())

        self._selecting = False
        """True if the user is selecting text with the mouse."""

        self._initial_value = True
        """Indicates if the value has been set for the first time yet."""
        if value is not None:

View on GitHub (pinned to 06dbeef4bb)

Solutions

Use an exact allowed literal, e.g. Input(type='integer').
Validate config-driven values against the allowed set before constructing Input.
Check the installed version's _RESTRICT_TYPES keys (from textual.widgets._input import _RESTRICT_TYPES) when unsure.
Omit type= entirely for plain text input.

Example fix

# before
field = Input(type='int')

# after
field = Input(type='integer')

Defensive patterns

Strategy: validation

Validate before calling

from textual.widgets._input import _RESTRICT_TYPES
assert input_type in _RESTRICT_TYPES, f'bad type {input_type!r}'
Input(type=input_type)

Type guard

from textual.widgets._input import _RESTRICT_TYPES

def is_valid_input_type(t: object) -> bool:
    return isinstance(t, str) and t in _RESTRICT_TYPES

Prevention

Use exact literals like 'integer', 'number', 'text', 'password'
Validate config-driven type strings against _RESTRICT_TYPES
Check docs for the installed Textual version

When it happens

Trigger: Passing type='int' or type='Integer' (wrong casing/spelling) to Input; passing a custom string not in _RESTRICT_TYPES; upgrading Textual where the allowed set changed.

Common situations: Copy-pasting Input(type=...) snippets from older docs/examples; dynamic type selection from config where an invalid value slips in; typos like 'interger'.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

AI-assisted analysis of Textualize/textual@06dbeef4bb (2026-08-27). Data as JSON: /api/errors/0ad827c2eca9ede1. Report an issue: GitHub.