How to Wait for Selector in Playwright?

Best practices

Use specific and unique selectors to ensure that `wait_for_selector` accurately targets the desired element on the page.
Set an appropriate timeout for `wait_for_selector` to avoid unnecessarily long waits, especially in environments with variable network conditions.
Utilize the `state` parameter in `wait_for_selector` to handle different visibility states of elements, such as 'visible', 'attached', or 'hidden', according to the needs of your test scenario.
Always handle potential exceptions from `wait_for_selector` to maintain the robustness of your script, especially in cases where the selector does not appear within the timeout period.

from playwright.sync_api import sync_playwright

# Initialize Playwright and start a browser
with sync_playwright() as p:
browser = p.chromium.launch()
page = browser.new_page()

# Navigate to the target website
page.goto('https://sandbox.oxylabs.io/products')

# Wait for a specific selector to be visible on the page
page.wait_for_selector('selector', state='visible')

# Wait for a selector to be attached to the DOM
page.wait_for_selector('selector', state='attached')

# Wait for a selector to be hidden or removed
page.wait_for_selector('selector', state='hidden')

# Optionally, set a timeout (in milliseconds)
page.wait_for_selector('selector', timeout=5000)

# Close the browser
browser.close()

Common issues

Ensure that the page navigation is complete before using `wait_for_selector` to avoid premature timeouts and errors.
Regularly update your selectors if the website undergoes changes to maintain the accuracy and reliability of your tests.
Consider using `wait_for_selector` with regex or CSS pseudo-classes for dynamic content that changes identifiers frequently.
Test your selectors in the browser's developer tools console to confirm they select the intended elements before implementing them in your script.

# Incorrect: Using wait_for_selector before the page has fully loaded
page.goto('https://example.com')
page.wait_for_selector('.dynamic-content', state='visible')

# Correct: Ensure page navigation is complete before waiting for selector
page.goto('https://example.com', wait_until='networkidle')
page.wait_for_selector('.dynamic-content', state='visible')

# Incorrect: Using outdated or incorrect selectors
page.wait_for_selector('.old-class-name', state='visible')

# Correct: Regularly check and update selectors to match the current page structure
page.wait_for_selector('.updated-class-name', state='visible')

# Incorrect: Using a simple selector for elements that change identifiers
page.wait_for_selector('#temp-id-123', state='visible')

# Correct: Use selectors that target stable attributes or patterns
page.wait_for_selector('[data-testid="submit-button"]', state='visible')

# Incorrect: Not testing selectors in development tools leading to failures in scripts
page.wait_for_selector('.non-existent-class', state='visible')

# Correct: Test selectors in the browser console to ensure they work as expected
page.wait_for_selector('.existing-class', state='visible')