pytest-dev/pytest · error · TypeError

{self.inipath}: config option '{name}' expects a string, got

Error message

{self.inipath}: config option '{name}' expects a string, got {value_type}: {value!r}

What it means

Raised by Config._getini_toml (config/__init__.py:2017-2023) for a 'string'-typed option in TOML mode when the value is not a Python str. TOML preserves native types, so a bare int/bool/float/list where a string is required is rejected (no coercion, unlike INI mode).

Source

Thrown at src/_pytest/config/__init__.py:2020

            # Expect an integer (but not bool, which is a subclass of int).
            if not isinstance(value, int) or isinstance(value, bool):
                raise TypeError(
                    f"{self.inipath}: config option '{name}' expects an int, "
                    f"got {value_type}: {value!r}"
                )
            return value
        elif type == "float":
            # Expect a float or integer only.
            if not isinstance(value, (float, int)) or isinstance(value, bool):
                raise TypeError(
                    f"{self.inipath}: config option '{name}' expects a float, "
                    f"got {value_type}: {value!r}"
                )
            return value
        elif type == "string":
            # Expect a string.
            if not isinstance(value, str):
                raise TypeError(
                    f"{self.inipath}: config option '{name}' expects a string, "
                    f"got {value_type}: {value!r}"
                )
            return value
        else:
            return self._getini_unknown_type(name, type, value)

    def _getconftest_pathlist(
        self, name: str, path: pathlib.Path
    ) -> list[pathlib.Path] | None:
        try:
            mod, relroots = self.pluginmanager._rget_with_confmod(name, path)
        except KeyError:
            return None
        assert mod.__file__ is not None
        modpath = pathlib.Path(mod.__file__).parent
        values: list[pathlib.Path] = []
        for relroot in relroots:

View on GitHub (pinned to 98b357f69e)

Solutions

Quote the value in TOML: x = "value".
Watch for barewords that TOML parses as int/bool (8, true) and wrap them in quotes.
Confirm the option's registered type is 'string' (or a Literal choice).

Example fix

# before (pyproject.toml)
[tool.pytest.ini_options]
minversion = 8

# after
minversion = "8.0"

Defensive patterns

Strategy: validation

Validate before calling

def ensure_toml_str(value):
    if not isinstance(value, str):
        raise TypeError('string option in TOML must be a quoted string')
    return value

Type guard

def is_str(value) -> bool:
    return isinstance(value, str)

Try / catch

try:
    config.getini(name)
except Exception:
    # quote the value in pyproject.toml and reload

Prevention

Quote string values in TOML, especially ones that look numeric/boolean.
Validate pyproject.toml pytest sections with a linter.
Beware barewords (8, true) parsed as non-string types.

When it happens

Trigger: Setting a string option in pyproject.toml to an unquoted bareword that TOML parses as a number/bool, e.g. minversion = 8 instead of minversion = "8".

Common situations: Forgetting quotes around values that look numeric or boolean (e.g. minversion, markers); INI->TOML migration; treating TOML like a shell config.

Related errors

AI-assisted analysis of pytest-dev/pytest@98b357f69e (2026-08-04). Data as JSON: /data/errors/1c42c1aa25eb8c9e.json. Report an issue: GitHub.