📄 playwright-python/python/docs/api/class-selectors

File: class-selectors.md | Updated: 11/18/2025

Source: https://playwright.dev/python/docs/api/class-selectors

Skip to main content

On this page

Selectors can be used to install custom selector engines. See extensibility for more information.

Methods​

register​

Added before v1.9 selectors.register

Selectors must be registered before creating the page.

Usage

An example of registering selector engine that queries elements based on a tag name:

  • Sync

  • Async

    from playwright.sync_api import sync_playwright, Playwrightdef run(playwright: Playwright): tag_selector = """ { // Returns the first element matching given selector in the root's subtree. query(root, selector) { return root.querySelector(selector); }, // Returns all elements matching given selector in the root's subtree. queryAll(root, selector) { return Array.from(root.querySelectorAll(selector)); } }""" # Register the engine. Selectors will be prefixed with "tag=". playwright.selectors.register("tag", tag_selector) browser = playwright.chromium.launch() page = browser.new_page() page.set_content('<div><button>Click me</button></div>') # Use the selector prefixed with its name. button = page.locator('tag=button') # Combine it with built-in locators. page.locator('tag=div').get_by_text('Click me').click() # Can use it in any methods supporting selectors. button_count = page.locator('tag=button').count() print(button_count) browser.close()with sync_playwright() as playwright: run(playwright)

    import asynciofrom playwright.async_api import async_playwright, Playwrightasync def run(playwright: Playwright): tag_selector = """ { // Returns the first element matching given selector in the root's subtree. query(root, selector) { return root.querySelector(selector); }, // Returns all elements matching given selector in the root's subtree. queryAll(root, selector) { return Array.from(root.querySelectorAll(selector)); } }""" # Register the engine. Selectors will be prefixed with "tag=". await playwright.selectors.register("tag", tag_selector) browser = await playwright.chromium.launch() page = await browser.new_page() await page.set_content('<div><button>Click me</button></div>') # Use the selector prefixed with its name. button = await page.query_selector('tag=button') # Combine it with built-in locators. await page.locator('tag=div').get_by_text('Click me').click() # Can use it in any methods supporting selectors. button_count = await page.locator('tag=button').count() print(button_count) await browser.close()async def main(): async with async_playwright() as playwright: await run(playwright)asyncio.run(main())

Arguments

  • name str #

    Name that is used in selectors as a prefix, e.g. {name: 'foo'} enables foo=myselectorbody selectors. May only contain [a-zA-Z0-9_] characters.

  • script str (optional)#

    Raw script content.

  • content_script bool (optional)#

    Whether to run this selector engine in isolated JavaScript environment. This environment has access to the same DOM, but not any JavaScript objects from the frame's scripts. Defaults to false. Note that running as a content script is not guaranteed when this engine is used together with other registered engines.

  • path Union [str
    , pathlib.Path
    ] (optional)#

    Path to the JavaScript file. If path is a relative path, then it is resolved relative to the current working directory.

Returns

set_test_id_attribute​

Added in: v1.27 selectors.set_test_id_attribute

Defines custom attribute name to be used in page.get_by_test_id() . data-testid is used by default.

Usage

selectors.set_test_id_attribute(attribute_name)

Arguments