python-dataservice

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DataService

Lightweight - async - data gathering for Python.

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DataService is a lightweight web scraping and general purpose data gathering library for Python.

Designed for simplicity, it's built upon common web scraping and data gathering patterns.

No complex API to learn, just standard Python idioms.

Dual synchronous and asynchronous support.

Installation

Please note that DataService requires Python 3.11 or higher.

You can install DataService via pip:

.. code-block:: bash

pip install python-dataservice

You can also install the optional playwright dependency to use the PlaywrightClient:

.. code-block:: bash

pip install python-dataservice[playwright]

To install Playwright, run:

.. code-block:: bash

python -m playwright install

or simply:

.. code-block:: bash

playwright install

How to use DataService

To start, create a DataService instance with an Iterable of Request objects. This setup provides you with an Iterator of data objects that you can then iterate over or convert to a list, tuple, a pd.DataFrame or any data structure of choice.

.. code-block:: python

start_requests = [Request(url="https://books.toscrape.com/index.html", callback=parse_books_page, client=HttpXClient())]
data_service = DataService(start_requests)
data = tuple(data_service)

A Request is a Pydantic model that includes the URL to fetch, a reference to the client callable, and a callback function for parsing the Response object.

The client can be any async Python callable that accepts a Request object and returns a Response object. DataService provides an HttpXClient class by default, which is based on the httpx library, but you are free to use your own custom async client.

The callback function processes a Response object and returns either data or additional Request objects.

In this trivial example we are requesting the Books to Scrape <https://books.toscrape.com/index.html>_ homepage and parsing the number of books on the page.

Example parse_books_page function:

.. code-block:: python

def parse_books_page(response: Response):
    articles = response.html.find_all("article", {"class": "product_pod"})
    return {
        "url": response.url,
        "title": response.html.title.get_text(strip=True),
        "articles": len(articles),
    }

This function takes a Response object, which has a html attribute (a BeautifulSoup object of the HTML content). The function parses the HTML content and returns data.

The callback function can return or yield either data (dict or pydantic.BaseModel) or more Request objects.

If you have used Scrapy before, you will find this pattern familiar.

For more examples and advanced usage, check out the examples <https://dataservice.readthedocs.io/en/latest/examples.html>_ section.

For a detailed API reference, check out the API <https://dataservice.readthedocs.io/en/latest/modules.html>_ section.