InvalidSelectorException而試圖識別機器人框架腹板元件

Question

ign-In | FAIL | InvalidSelectorException: Message: The given selector xpath= //*[@id='user_email'] is either invalid or does not result in a WebElement. The following error occurred: InvalidSelectorError: Unable to locate an element with the xpath expression xpath= //*[@id='user_email'] because of the following error: TypeError: The expression cannot be converted to return the specified type. Stacktrace: at FirefoxDriver.annotateInvalidSelectorError_ (file:///var/folders/5f/6mvs5x1j37s5q3_38kjfwkgr0000gn/T/tmp1Nrpuj/webdriver-py-profilecopy/extensions/fxdriver@googlecode.com/components/driver-component.js:10633) at FirefoxDriver.prototype.findElementsInternal_ (file:///var/folders/5f/6mvs5x1j37s5q3_38kjfwkgr0000gn/T/tmp1Nrpuj/webdriver-py-profilecopy/extensions/fxdriver@googlecode.com/components/driver-component.js:10691) at FirefoxDriver.prototype.findElements (file:///var/folders/5f/6mvs5x1j37s5q3_38kjfwkgr0000gn/T/tmp1Nrpuj/webdriver-py-profilecopy/extensions/fxdriver@googlecode.com/components/driver-component.js:10695) at DelayedCommand.prototype.executeInternal_/h (file:///var/folders/5f/6mvs5x1j37s5q3_38kjfwkgr0000gn/T/tmp1Nrpuj/webdriver-py-profilecopy/extensions/fxdriver@googlecode.com/components/command-processor.js:12534) at DelayedCommand.prototype.executeInternal_ (file:///var/folders/5f/6mvs5x1j37s5q3_38kjfwkgr0000gn/T/tmp1Nrpuj/webdriver-py-profilecopy/extensions/fxdriver@googlecode.com/components/command-processor.js:12539) at DelayedCommand.prototype.execute/< (file:///var/folders/5f/6mvs5x1j37s5q3_38kjfwkgr0000gn/T/tmp1Nrpuj/webdriver-py-profilecopy/extensions/fxdriver@googlecode.com/components/command-processor.js:12481)

Answer 1

錯誤消息的這部分解釋了爲何：

The given selector xpath= //*[@id='user_email'] is either invalid or does not result in a WebElement .

在這種情況下，//*[@id='user_email']是有效的XPath表達式，所以它必須由沒有元素匹配那個XPath。從我提供的信息中我可以看出這一點。