How to Correctly Select a CSS Class with XPath?

Selecting a CSS Class with XPath

In the context of web scraping, accurately targeting specific elements based on their CSS classes is crucial. While CSS selectors are straightforward when working with HTML, XPath becomes necessary when dealing with XML documents or utilizing advanced web scraping techniques.

Problem: Selecting a Single Class with XPath

This question stems from the need to select elements based solely on their "date" class using XPath. However, the provided code snippet produces unexpected results.

//[@class="date"]

Solution: The Correct XPath Equivalent

To properly select elements with a specific class in XPath, the following syntax should be used:

//*[contains(concat(" ", normalize-space(@class), " "), " foo ")]

In this expression:

• normalize-space(@class) removes leading and trailing spaces and collapses multiple spaces into one, ensuring that the class attribute is consistently formatted.
• concat(" ", normalize-space(@class), " ") adds spaces around the normalized class value to make it comparable to the target class name.
• contains(...) searches for the target class name within the modified class attribute value.

Avoiding Incorrect Approaches

Two common but flawed XPath selectors to avoid include:

• //*[@class="date"]: Does not account for elements with multiple classes.
• //*[contains(@class, "date")]: Matches elements with class names containing "date", such as "foobar," which is incorrect.

Credit

The solution provided here is attributed to a fellow web scraper who published a valuable blog post addressing this specific issue. Our gratitude goes to them for sharing their insights.

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