scrapy/scrapy · error · TypeError

Request priority not an integer: {priority!r}

Error message

Request priority not an integer: {priority!r}

What it means

Request.__init__ raises TypeError when the priority argument is not an int (bool counts as int and passes; floats and strings do not). Priority is used directly by built-in schedulers for ordering and must be an exact integer to keep comparisons and deque ordering deterministic; a bool like True would silently work as 1, but 1.0 or '1' fail this guard before any scheduling happens.

Source

Thrown at scrapy/http/request/__init__.py:149

        | Iterable[tuple[str | bytes, Any]]
        | None = None,
        body: bytes | str | None = None,
        cookies: CookiesT | None = None,
        meta: dict[str, Any] | None = None,
        encoding: str = "utf-8",
        priority: int = 0,
        dont_filter: bool = False,
        errback: Callable[[Failure], Any] | None = None,
        flags: list[str] | None = None,
        cb_kwargs: dict[str, Any] | None = None,
    ) -> None:
        self._encoding: str = encoding  # this one has to be set first
        self.method: str = str(method).upper()
        self._meta: dict[str, Any] | None = dict(meta) if meta else None
        self._set_url(url)
        self._set_body(body)
        if not isinstance(priority, int):
            raise TypeError(f"Request priority not an integer: {priority!r}")

        #: Default: ``0``
        #:
        #: Value that the :ref:`scheduler <topics-scheduler>` may use for
        #: request prioritization.
        #:
        #: Built-in schedulers prioritize requests with a higher priority
        #: value.
        #:
        #: Negative values are allowed.
        self.priority: int = priority

        if not (callable(callback) or callback is None):
            raise TypeError(
                f"callback must be a callable, got {type(callback).__name__}"
            )
        if not (callable(errback) or errback is None):
            raise TypeError(f"errback must be a callable, got {type(errback).__name__}")

View on GitHub (pinned to 06af687662)

Solutions

1. Coerce to int at the call site: priority=int(priority) after validating the value
2. If you need fractional ordering, scale to integers (e.g. priority * 100 as int) since built-in schedulers only accept int
3. Cast external config once at load: priority = int(settings['PRIORITY'])
4. Add a unit assertion in helpers that build requests from untrusted data: isinstance(priority, int)

Example fix

# before
Request(url, priority=0.5)      # TypeError
Request(url, priority='10')     # TypeError

# after
Request(url, priority=1)
Request(url, priority=int('10'))
# scaled fractional ordering:
Request(url, priority=int(0.5 * 100))

if not isinstance(priority, int):
    priority = int(priority)  # or raise with context
Request(url, priority=priority)

def is_valid_priority(p) -> bool:
    return isinstance(p, int) and not isinstance(p, bool) or isinstance(p, bool)

null

When it happens

Trigger: Request(url, priority=1.5) or priority=float(some_setting); priority computed as '10' from a string config; passing a numpy integer type (not a Python int, so isinstance fails); templated code where priority comes from an untyped source like CSV/JSON.

Common situations: Priority read from settings/env as string and not converted; float arithmetic ('base + 0.5 * depth') feeding priority; interop with libraries returning non-int numerics (numpy.int64 is actually fine on CPython but Decimal/float are not).

Related errors

• callback must be a callable, got {type(callback).__name__}
• errback must be a callable, got {type(errback).__name__}
• Request url must be str, got {type(url).__name__}
• Unsupported value type: {type(x)}
• Invalid value {value} for component {name}, please provide a

AI-assisted analysis of scrapy/scrapy@06af687662 (2026-08-15). Data as JSON: /api/errors/0e41b58d7c0044cb. Report an issue: GitHub.