WebRunner.py 文件源码

def wait_for_presence(self, selector='', **kwargs):
        '''
        Wait for an element to be present. (Does not need to be visible.)

        Parameters
        ----------
        selector: str
            A CSS selector to search for. This can be any valid CSS selector.

        kwargs:
            Passed on to _wait_for

        '''
        if selector.startswith('/'):
            by = By.XPATH
        else:
            by = By.CSS_SELECTOR
        self._wait_for(EC.presence_of_element_located((by, selector)) or
                       EC.presence_of_elements_located((by, selector)),
                       **kwargs)