Python is also a widely used language for building Selenium WebDriver tests. It offers various ways to parameterize tests.
In this recipe, we will use the DDT module along with unittest to create a parameterized test.
You need to install the DDT module by using the following command:
pip install ddt
This command will download and install all the dependencies required for DDT on your machine.
Let's create a simple Python test for parameterization using the DDT module. Create a new Python file named bmi_calc_ddt.py using the following code:
import unittest
from ddt import ddt, data, unpack
from selenium import webdriver
@ddt
class BmiCalcDDT(unittest.TestCase):
def setUp(self):
# create a new Firefox session
self.driver = webdriver.Firefox()
self.driver.implicitly_wait(30)
self.driver.maximize_window()
# navigate to the BMI Calculator page
self.driver.get("http://bit.ly/1zdNrFZ")
# specify test data using @data decorator
@data(("160", "45", "17.6", "Underweight"),
("168", "70", "24.8", "Normal"),
("181", "89", "27.2", "Overweight"))
@unpack
def test_bmi_calc(self, height, weight, bmi, category):
driver = self.driver
height_field = driver.find_element_by_name("heightCMS")
height_field.clear()
height_field.send_keys(height)
weight_field = driver.find_element_by_name("weightKg")
weight_field.clear()
weight_field.send_keys(weight)
calculate_button = driver.find_element_by_id("Calculate")
calculate_button.click()
bmi_label = driver.find_element_by_name("bmi")
bmi_category_label = driver.find_element_by_name("bmi_category")
self.assertEqual(bmi, bmi_label.get_attribute("value"))
self.assertEqual(category, bmi_category_label.get_attribute("value"))
def tearDown(self):
# close the browser window
self.driver.quit()
if __name__ == '__main__':
unittest.main(verbosity=2)The DDT module is an extension for the Python unittest library. We can use this module to parameterize unit tests in Python. We need to add a special decorator @ddt to parameterize the test class:
@ddt class BmiCalcDDT(unittest.TestCase):
Next, we need to describe the test data above the test method using the @data decorator:
# specify test data using @data decorator
@data(("160", "45", "17.6", "Underweight"),
("168", "70", "24.8", "Normal"),
("181", "89", "27.2", "Overweight"))
@unpackWhen we execute this test, Python will read the data tuples and pass each row to the test.