Browser applications testing using Selenium with Python

Selenium:

Selenium is a web application testing framework that allows you to write tests in many programming languages like  Java, C#, Groovy, Perl, PHP, Python and Ruby. Selenium deploys on Windows, Linux, and MAC OS.

Selenium Components:

Selenium IDE is a Firefox add-on that records user activity and creates a test case based on it. It can also play the tests back and save them as a program in different languages.

Selenium RC (aka Selenium Remote Control or Selenium 1) receives Selenium Core commands via HTTP and executes them on a remote machine, proxying the web browser in order to avoid the “same host origin” restriction. This also allows writing the tests in other languages like C#, Python, Perl, PHP, Java and Ruby (via language bindings for Selenium Core).

Selenium-WebDriver (aka WebDriver or Selenium 2) is a successor of Selenium RC. It does the same job, but in a different way: instead of injecting a JavaScript code into the browser to simulate user actions, it uses the browser’s native support for automation (different for each browser). Also, instead of a dictionary-based API (used in Selenium RC), it offers the more convenient object-oriented API.

different browsers web drivers link(http://www.seleniumhq.org/download/)

Selenium-Grid allows you run the tests on different machines against different browsers in parallel; in other words it enables distributed test execution.

Selenium Server allows using Selenium-WebDriver on a remote machine.

Where to Start:

It’s good to start with Selenium IDE. It will help you to become more familiar with Selenium commands, and you can see how Selenium works by running the test scripts right from this tool. Note, however, that when you run your test scripts from Selenium IDE, they are executed in a different way than when you run them through other Selenium tools. If you need to test your application, you’d better use Selenium WebDriver or Selenium RC. I put Selenium WebDriver first, because it is the successor of Selenium RC which  has been officially deprecated.

You can download everything at http://docs.seleniumhq.org/download/.

Python Binding package for selenium:

Selenium Python bindings provides a simple API to write functional/acceptance tests using Selenium WebDriver. Through Selenium Python API you can access all functionalities of Selenium WebDriver in an intuitive way.

Selenium Python bindings provide a convenient API to access Selenium WebDrivers like Firefox, Ie, Chrome, Remote etc. The current supported Python versions are 2.7, 3.2, 3.3 and 3.4.

Download python bindings:

You can download Python bindings for Selenium from the PyPI page for selenium package. However, a better approach would be to use pip to install the selenium package. Python 3.4 has pip available in the standard library. Using pip, you can install selenium like this:

pip install selenium

You may consider using virtualenv to create isolated Python environments. Python 3.4 has pyvenv which is almost same as virtualenv.

Small example:

If you have installed Selenium Python bindings, you can start using it from Python like this.

from selenium import webdriver
from selenium.webdriver.common.keys import Keys

driver = webdriver.Firefox()
driver.get("http://www.python.org")
assert "Python" in driver.title
elem = driver.find_element_by_name("q")
elem.send_keys("pycon")
elem.send_keys(Keys.RETURN)
assert "No results found." not in driver.page_source
driver.close()

The above script can be saved into a file (eg:- python_org_search.py), then it can be run like this:
python python_org_search.py

Explanation about script:

The selenium.webdriver module provides all the WebDriver implementations. Currently supported WebDriver implementations are Firefox, Chrome, Ie and Remote. The Keys class provide keys in the keyboard like RETURN, F1, ALT etc.

from selenium import webdriver
from selenium.webdriver.common.keys import Keys

Next, the instance of Firefox WebDriver is created.

driver = webdriver.Firefox()

The driver.get method will navigate to a page given by the URL. WebDriver will wait until the page has fully loaded (that is, the “onload” event has fired) before returning control to your test or script. It’s worth noting that if your page uses a lot of AJAX on load then WebDriver may not know when it has completely loaded.:

driver.get("http://www.python.org")

The next line is an assertion to confirm that title has “Python” word in it:

assert "Python" in driver.title

WebDriver offers a number of ways to find elements using one of the find_element_by_* methods. For example, the input text element can be located by its name attribute using find_element_by_name method. Detailed explanation of finding elements is available in the Locating Elements chapter:

elem = driver.find_element_by_name("q")

Next we are sending keys, this is similar to entering keys using your keyboard. Special keys can be send using Keys class imported from selenium.webdriver.common.keys:

elem.send_keys("pycon")
elem.send_keys(Keys.RETURN)

After submission of the page, you should get the result if there is any. To ensure that some results are found, make an assertion:

assert "No results found." not in driver.page_source

Finally, the browser window is closed. You can also call quit method instead of close. The quit will exit entire browser where as close will close one tab, but if it just one tab, by default most browser will exit entirely.:

driver.close()


For Complete Reference of Python With Selenium:
link (http://selenium-python.readthedocs.org/)
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