D4Vinci/Scrapling · error · ValueError

Filename must be provided

Error message

Filename must be provided

What it means

write_content_to_file validates that filename is a non-empty, non-whitespace string before use. An empty/None filename, a non-str value, or a whitespace-only string raises ValueError('Filename must be provided'). This fires before the extension check and before the file is opened.

Source

Thrown at scrapling/core/shell.py:665

                            "\n",
                            "\r",
                            "\t",
                            " ",
                        ):
                            # Remove consecutive white-spaces
                            txt_content = TextHandler(re_sub(f"[{s}]+", s, txt_content))
                        yield txt_content
            yield ""

    @classmethod
    def write_content_to_file(
        cls, page: Selector, filename: str, css_selector: Optional[str] = None, main_content_only: bool = False
    ) -> None:
        """Write a Selector's content to a file"""
        if not page or not isinstance(page, Selector):  # pragma: no cover
            raise TypeError("Input must be of type `Selector`")
        elif not filename or not isinstance(filename, str) or not filename.strip():
            raise ValueError("Filename must be provided")
        elif not filename.endswith((".md", ".html", ".txt")):
            raise ValueError("Unknown file type: filename must end with '.md', '.html', or '.txt'")
        else:
            with open(filename, "w", encoding=page.encoding) as f:
                extension = filename.split(".")[-1]
                f.write(
                    "".join(
                        cls._extract_content(
                            page,
                            cls._extension_map[extension],
                            css_selector=css_selector,
                            main_content_only=main_content_only,
                        )
                    )
                )

View on GitHub (pinned to 5d213a2d47)

Solutions

1. Default the filename explicitly, e.g. filename = filename or 'output.md'
2. Validate required path config before calling (fail fast at the boundary)
3. In CLI code, make the output option required=True instead of defaulting to None

Example fix

# before
Convertor.write_content_to_file(page, args.output)  # args.output is None

# after
Convertor.write_content_to_file(page, args.output or 'output.html')

filename = (filename or '').strip() or 'output.html'
assert isinstance(filename, str) and filename, 'filename required'

from typing import Any

def is_valid_filename(value: Any) -> bool:
    return isinstance(value, str) and bool(value.strip())

When it happens

Trigger: Calling write_content_to_file(page, filename=None) or '' — typically because a path variable from config/argv came through unset, or a f-string built the name from a missing key.

Common situations: Optional CLI args or config keys (output file) not provided while the code forwards them anyway; templated filenames where a substitution evaluated to empty.

Related errors

• Unknown file type: filename must end with '.md', '.html', or
• Unknown extraction type: {extraction_type}
• Invalid JSON data '{json_string}': {err}
• Could not parse cookies '{cookies}': {err}
• Credentials dictionary must contain both 'username' and 'pas

AI-assisted analysis of D4Vinci/Scrapling@5d213a2d47 (2026-08-14). Data as JSON: /api/errors/af9c317f9c9304df. Report an issue: GitHub.