How to get selected option using Selenium WebDriver with Java

You should be able to get the text using getText() (for the option element you got using getFirstSelectedOption()):

Select select = new Select(driver.findElement(By.xpath("//select")));
WebElement option = select.getFirstSelectedOption();
String defaultItem = option.getText();
System.out.println(defaultItem );

On the following option:

WebElement option = select.getFirstSelectedOption();
option.getText();

If from the method getText() you get a blank, you can get the string from the value of the option using the method getAttribute:

WebElement option = select.getFirstSelectedOption();
option.getAttribute("value");

In Selenium Python it is:

from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support.ui import Select

def get_selected_value_from_drop_down(self):
    try:
        select = Select(WebDriverWait(self.driver, 20).until(EC.element_to_be_clickable((By.ID, 'data_configuration_edit_data_object_tab_details_lb_use_for_match'))))
        return select.first_selected_option.get_attribute("value")
    except NoSuchElementException, e:
        print "Element not found "
        print e

Completing the answer:

String selectedOption = new Select(driver.findElement(By.xpath("Type the xpath of the drop-down element"))).getFirstSelectedOption().getText();

Assert.assertEquals("Please select any option...", selectedOption);