typed-soup 0.1.5

A type-safe wrapper around BeautifulSoup and related HTML parsing utilities

typed-soup

A type-safe wrapper around BeautifulSoup and utilities for parsing HTML/XML with robust return types and error handling. Extracted from Open-Gov Crawlers.

Motivation

This is an example from production code.

Before

Here are the first five errors. There are 16 in total.

  error: Type of "rows" is partially unknown
    Type of "rows" is "list[PageElement | Tag | NavigableString] | Unknown" (reportUnknownVariableType)
  error: Type of "find_all" is partially unknown
    Type of "find_all" is "Unknown | ((name: str | bytes | Pattern[str] | bool | ((Tag) -> bool) | Iterable[str | bytes | Pattern[str] | bool | ((Tag) -> bool)] | ElementFilter | None = None, attrs: Dict[str, str | bytes | Pattern[str] | bool | ((str) -> bool) | Iterable[str | bytes | Pattern[str] | bool | ((str) -> bool)]] = {}, recursive: bool = True, string: str | bytes | Pattern[str] | bool | ((str) -> bool) | Iterable[str | bytes | Pattern[str] | bool | ((str) -> bool)] | None = None, limit: int | None = None, _stacklevel: int = 2, **kwargs: str | bytes | Pattern[str] | bool | ((str) -> bool) | Iterable[str | bytes | Pattern[str] | bool | ((str) -> bool)]) -> ResultSet[PageElement | Tag | NavigableString])" (reportUnknownMemberType)
  error: Cannot access attribute "find_all" for class "PageElement"
    Attribute "find_all" is unknown (reportAttributeAccessIssue)
  error: Cannot access attribute "find_all" for class "NavigableString"
    Attribute "find_all" is unknown (reportAttributeAccessIssue)
  error: Type of "row" is partially unknown
    Type of "row" is "PageElement | Tag | NavigableString | Unknown" (reportUnknownVariableType)

After

Switching out BeautifulSoup for TypedSoup provides type knowledge to the checker and IDE:

Installation

pip install typed-soup

Quick Start

from typed_soup import TypedSoup
from bs4 import BeautifulSoup

# Create a type-safe soup object
soup = TypedSoup(BeautifulSoup("<div>Hello <span>World</span></div>", "html.parser"))

# Find elements with type safety
element = soup.find("span")
if element:
    print(element.get_text())  # Type-safe: IDE knows this returns str

Usage

If you're using Scrapy, you can use the from_response function to create a TypedSoup object from a Scrapy response:

from typed_soup import from_response
from scrapy.http.response.html import HtmlResponse

# Assume 'response' is an HtmlResponse object
soup = from_response(response)

# Find an element
element = soup.find("div", class_="example")
if element:
    print(element.get_text())

# Find all elements
elements = soup("p")
for elem in elements:
    print(elem.get_text())

Or, without Scrapy, you can explicity wrap a BeautifulSoup object in TypedSoup:

from typed_soup import TypedSoup
from bs4 import BeautifulSoup

soup = TypedSoup(BeautifulSoup(html_content, "html.parser"))

Supported Functions

I'm adding functions as I need them. If you have a request, please open an issue. These are the ones that I needed for a dozen spiders:

• find
• find_all
• __call__ (implicit find_all, e.g. soup("p") - standard BeautifulSoup API)
• get_text
• children
• tag_name
• parent
• next_sibling
• get_content_after_element
• string

And then these help create a TypedSoup object:

• from_response
• TypedSoup

Type Safety Benefits

• All methods return properly typed results
• No more None surprises - optional values are properly typed and described in the function signatures
• IDE autocomplete support for all methods
• Static type checking support with mypy/pyright
• Runtime type validation for BeautifulSoup results

License

This project is licensed under the MIT License.