如何使用％s在python中为Selenium构造带有变量的xpath表达式

Question

I am trying to use selenium to locate and select a certain element based on a variable passed into the function when it is called. I thought this would be simple enough with a good ol:

show = browser.find_element_by_xpath("//*[contains(text(), '%s')]" % eventName)

However, I receive error:

selenium.common.exceptions.InvalidSelectorException: Message: invalid selector: Unable to locate an element with the xpath expression //*[contains(text(), 'VARIABLE_TEXT')] because of the following error:
SyntaxError: Failed to execute 'evaluate' on 'Document': The string '//*[contains(text(), 'VARIABLE_TEXT')]' is not a valid XPath expression.

Here is--distilled and simplified--the part of the HTML I am attempting to select:

<ul>
<li class="seriesElement">
<input id="productionId_0" name="productionIds" type="checkbox" value="VALUE"><input type="hidden" name="_productionIds" value="on"><label for="productionId_0" class="prodColor0">TEXT</label>
</li>
<li class="seriesElement">
<input id="productionId_1" name="productionIds" type="checkbox" value="VALUE"><input type="hidden" name="_productionIds" value="on"><label for="productionId_1" class="prodColor1">TEXT</label>
</li>
</ul>

There are many of these list elements, and I want to select one by the text. Have I just used the wrong syntax for my xpath expression, or is this a different beast entirely?

Answer 1

You can try this way.See if this helps.

VAR_TEXT="TEXT"
print(driver.find_element_by_xpath("//label[contains(text() ,'" + VAR_TEXT + "')]").text)

OR

VAR_TEXT="TEXT"
print(driver.find_element_by_xpath("//*[contains(text() ,'" + VAR_TEXT + "')]").text)

OR

VAR_TEXT="TEXT"
print(driver.find_element_by_xpath("//label[text()[contains(.,'" + VAR_TEXT + "')]]").text)

OR

VAR_TEXT="TEXT"
print(driver.find_element_by_xpath("//*[text()[contains(.,'" + VAR_TEXT + "')]]").text)

Answer 2

To locate a certain element based on it's variable text you can write a method as follows:

• Using . :

   def find_myelement_with_text(myString): show = browser.find_element_by_xpath("//label[.='" + myString + "']") 

• Using %s :

   def find_myelement_with_text(myString): show = browser.find_element_by_xpath("//label[contains(text(), '%s')]" % (myString)) 

• Using format() :

   def find_myelement_with_text(myString): show = browser.find_element_by_xpath('//label[contains(text(), "{}")]'.format(myString)) 

Now you can call this method from anywhere within your program as follows:

find_myelement_with_text("TEXT")

Answer 3

The good ol' 😀 %s worked as expected - you can see the substitution in the error message, the problem is with the xpath itself.
If you run it through a standalone parser (not the browser's one), you'll see the culprit for the error:

Unable to perform XPath operation. A sequence of more than one item is not allowed as the first argument of contains() ("", "", ...)

(that's a Java one, the text will be similar for other ones)

Long story short it's the output of text() that bothers it - it's a nodeset; if you change that function to a . , it should work:

show = browser.find_element_by_xpath("//*[contains(., '%s')]" % eventName)