D4Vinci/Scrapling · error · TypeError

Only string values are accepted for arguments

Error message

Only string values are accepted for arguments

What it means

Keyword arguments passed to find_all() must have string values, since kwargs are translated into CSS attribute selectors like tag[attr="value"]. A non-string kwarg value (int, bool, list, None) fails the all() check and raises TypeError before any searching starts.

Source

Thrown at scrapling/parser.py:751

                    )
                attributes.update(arg)

            elif isinstance(arg, re_Pattern):
                patterns.add(arg)

            elif callable(arg):
                if len(signature(arg).parameters) > 0:
                    functions.append(arg)
                else:
                    raise TypeError(
                        "Callable filter function must have at least one argument to take `Selector` objects."
                    )

            else:
                raise TypeError(f'Argument with type "{type(arg)}" is not accepted, please read the docs.')

        if not all([(isinstance(k, str) and isinstance(v, str)) for k, v in kwargs.items()]):
            raise TypeError("Only string values are accepted for arguments")

        for attribute_name, value in kwargs.items():
            # Only replace names for kwargs, replacing them in dictionaries doesn't make sense
            attribute_name = _whitelisted.get(attribute_name, attribute_name)
            attributes[attribute_name] = value

        # It's easier and faster to build a selector than traversing the tree
        tags = tags or set("*")
        for tag in tags:
            selector = tag
            for key, value in attributes.items():
                value = value.replace('"', r"\"")  # Escape double quotes in user input
                # Not escaping anything with the key so the user can pass patterns like {'href*': '/p/'} or get errors :)
                selector += '[{}="{}"]'.format(key, value)
            if selector != "*":
                selectors.append(selector)

        if selectors:

View on GitHub (pinned to 5d213a2d47)

Solutions

1. Stringify values when building kwargs: {'data-count': str(val)}.
2. For boolean attributes use the string form: find_all('input', disabled='disabled') rather than disabled=True.
3. Skip None values when forwarding: {k: v for k, v in attrs.items() if v is not None}.

Example fix

# before
selector.find_all('input', data_count=3)  # TypeError

# after
selector.find_all('input', data_count='3')

kwargs = {k: str(v) for k, v in kwargs.items() if v is not None}
selector.find_all('div', **kwargs)

def kwargs_are_strings(kwargs: dict) -> bool:
    return all(isinstance(v, str) for v in kwargs.values())

When it happens

Trigger: find_all('div', data_count=3), find_all(id=123), or find_all('a', href=None). Note the check applies only to values — keys are Python identifiers and inherently strings.

Common situations: Forwarding **kwargs from a config dict or JSON where numbers are parsed as int/float; passing a count limit kwarg that collides with an attribute filter.

Related errors

• Nested Iterables are not accepted, only iterables of tag nam
• Nested dictionaries are not accepted, only string keys and s
• Argument with type "{type(arg)}" is not accepted, please rea
• Response meta should be dictionary but got {type(meta).__nam
• Invalid proxy string: {proxy_string}

AI-assisted analysis of D4Vinci/Scrapling@5d213a2d47 (2026-08-14). Data as JSON: /api/errors/1df31894caea9cc4. Report an issue: GitHub.