python download pdf chrome driver How to download dynamically loaded content using python. When you surf online, you occasionally visit websites that show content like videos or audio files which are dynamically loaded. This is basically done using calls or sessions where the URLs for these files are generated in some way for which you can not save them by normal means. A scenario would be like, for example, you visited a web page and a video is loaded through a video player like jwplayer after 1 or 2 secs. You want to save this but unfortunately you couldn’t do so by right-clicking on it and saving it as the player doesn’t show that option. Even if you use command line tool like wget or youtube-dl, it might be possible but for some reason it just doesn’t work. Another problem is that, there are still some functions that need to be executed and until then, the video url does not get generated in the site. Now the question is, how would you download such files to your computer? Well, there are different ways to download them. One way is to use a plugin or extension for the browser like Grab Any Media or FlashGot which can handle such requests and might allow you to download it. Now the thing is, lets say you want to download an entire set of videos that are loaded using different AJAX calls. In this case, the plugins or extensions, might work but it takes a long time to manually download each file. A better method would be to write a small script that automates this process. This tutorial aims to teach you guys on how to use the selenium web driver and do simple tasks like downloading dynamically loaded content in a website using python. Prerequisites. For this tutorial, you need to have atleast some knowledge on how to program in python. If you don’t know anything about it, then I would suggest you to check out this site : http://www.tutorialspoint.com/python/. It is a great starting point to learn a new language and you can quickly learn the basics. So, before we start, I would like to give an small introduction to the modules that I am going to use in my python script. The system that I’m using is a Ubuntu Studio 14.04. In order to install the modules, you can use python-pip and also you might need to have administrative privileges. Here are the modules as follows : : The selenium framework is a suite of tools that can be used to test web applications and also automate the tasks. By using it’s provided API, you can do simple tasks like automating administration work for a website or some website-related maintenance, by sending commands to the browser. It is supported in various programming languages like Python, Java, Javascript, PHP, C#, Perl, Ruby. To install this framework for python, just type the following command in the terminal : : The bs4 is a HTML/XML parser that does a great job at screen-scraping elements and getting information like the tag names, attributes, and values. It also has set of methods that allow you do things like, to match certain instances of a text and retrieve all the elements that contain it. You can install this module like this : : This module is a python port for the wget command-line program. Its easy to setup and you can quickly download videos or files to your system by using its API. You can also follow the “traditional” method of downloading files, like using the standard urllib module or by doing a subprocess call to the wget command-line program, but for this tutorial, I will be using this module to get the job done. Here is how you install it : (Optional) : The PhantomJS is a headless browser (doesn’t have a front-end GUI and everything works at the backend) that is used for web page interaction. It is similar to the selenium web driver but the difference is that, it is headless. For this tutorial, I will be using the basic web driver via selenium, but you can test this out if you do not want a browser to popup every time the script runs. You can download the executable from their homepage, but I advise you to use a downgraded version of this as the latest one might not be compatible with selenium module. The Concept. The idea is basically : To get the web page using the selenium web driver. Parse and extract the video or audio urls from the html page using BeautifulSoup. Download the files to the system using wget. Step 1. The first step we need to do is import the necessary modules in the python script or shell, and this can be done as shown below : From the selenium module, we import the following things : webdriver : This submodule has the functionality to initialize the various browsers like Chrome, Firefox, IE, etc. Keys : This allows us to send key presses or inputs to the web driver. WebDriverWait : The WebDriverWait is similar to the sleep function of the time module. This function tells the webdriver to wait for "n" seconds. expected_conditions : There are common conditions that the web driver takes into account like, for example, a condition would be for an element to appears in the browser or when the title of the page is somename . Here is a list of all the available conditions 1 : title_is title_contains presence_of_element_located visibility_of_element_located visibility_of presence_of_all_elements_located text_to_be_present_in_element text_to_be_present_in_element_value frame_to_be_available_and_switch_to_it invisibility_of_element_located element_to_be_clickable - it is Displayed and Enabled. staleness_of element_to_be_selected element_located_to_be_selected element_selection_state_to_be element_located_selection_state_to_be alert_is_present. Step 2. Now, according to the concept, for a single video url that is loaded using an AJAX call, we need to get the web page using the selenium webdriver. This is done as follows : When you execute this in the python shell or via the script (after you import the modules), you will observe that, a firefox browser will popup and a page will be loaded into it. If you want to use the PhantomJS and stop the browser from popping up, then just replace the webdriver.Firefox() with webdriver.PhantomJS(service_args=['--ignore-ssl-errors=true']) . Step 3. Here is the tricky part, what you need to do is extract the video urls from the web page. As every website is designed differently, you don’t have an accurate solution. You would need to manually check for a pattern or the video element that is dynamically loaded. This can be done by looking at the browser’s developer console. From the previously mentioned scenario, lets say the video is dynamically loaded using a AJAX call after 1 sec you visit the website. Then you would need to wait till the video is loaded and then get the element. So, for that you can write the script in this manner : When you execute these two lines in the python shell, it will tell the browser to wait for 50 seconds by default until the element with the specific id appears or is visible on the screen, and then get the html source. Now if the element doesn’t have an ID, there are other ways you can get the specific element/tag. Lets say the element has a certain class, then you can just replace the By.ID with By.CLASS_NAME . Here is the entire list of attributes for the By class object 2 : ID XPATH LINK_TEXT PARTIAL_LINK_TEXT NAME TAG_NAME CLASS_NAME CSS_SELECTOR. Step 4. Once you get the HTML source, you would need to parse it and extract the video tag from it. This is done as shown below : The list_of_attributes is a python dictionary, with (key,value) pairs which specify the tags attributes. The parser.findAll() searches the entire HTML source and gets the video tags with the specific attributes. This generates a multi-dimensional array and is stored in the tag variable. Step 5. The next step is to get the url from the video tag and finally download it using wget. We can do this by writing the script in this manner : Depending on the number of videos loaded in the web page, you can specify which video you want to download. This can by done changing the value of n . Step 6. Finally, once the job is done, we close the driver : The script. Now, when you put all the pieces together, and with some additional functionality to login to a website, you will get something like this : Conclusion. What we did in this tutorial is, to create a small script that automates the process of downloading a file which is dynamically loaded. The above script works for a single url. If you want to download multiple files, then you would need to manually grab the tags and dynamic content information of each website and store them in json or xml file. Then you would need to read that file and pass it through a for loop. I created another small script that does this job. Its not full proof but is a good starting point for you guys to get an idea on how to do it. It also accepts command line arguments that allow you to download either a single video file or by taking in a file that contains all the video urls. You can get the script here : https://gitlab.com/snippets/8921. Please keep in mind that, you will encounter some websites which are so secure, that even though what you do, you just cannot download that video or file. This is because, they are designed in such a way that, the urls for the files are generated with unique id and is embedded into the site. Waits. An implicit wait instructs Selenium WebDriver to poll DOM for a certain amount of time, this time can be specified, when trying to find an element or elements that are not available immediately. Explicit Waits. Explicit wait make the webdriver wait until certain conditions are fulfilled . Example of a wait. List of explicit waits. title_is title_contains presence_of_element_located visibility_of_element_located visibility_of presence_of_all_elements_located text_to_be_present_in_element text_to_be_present_in_element_value frame_to_be_available_and_switch_to_it invisibility_of_element_located element_to_be_clickable staleness_of element_to_be_selected element_located_to_be_selected element_selection_state_to_be element_located_selection_state_to_be alert_is_present. Loading a list of elements like li and selecting one of the element. Read Attribute. Get CSS. CSS values varies on different browser, you may not get same values for all the browser. Capture Screenshot. save_screenshot(“filename”) and get_screenshot_as_file(“filename) will work only when the extension of file is “png”. Otherwise the content cannot be viewed. is_selected() is_selected() method in selenium verifies if an element (such as checkbox) is selected or not. is_selected() method returns a boolean. is_displayed() is_displayed() method in selenium webdriver verifies and returns a boolean based on the state of the element (such as button) whether it is displayed or not. is_enabled() is_enabled() method in selenium python verifies and returns a boolean based on the state of the element (such as button) whether it is enabled or not. Selenium with Python: Tutorial on Test Automation. In an agile environment, developers emphasize pushing changes quickly. With every change that requires a modification to the front end, they need to run appropriate cross browser tests. While a small project may choose manual testing, an increasing number of browsers make a case for automation testing. In this post, we provide a step-by-step tutorial of web automation testing through Selenium and Python. Selenium allows you to define tests and automatically detect the results of these tests on a pre-decided browser. A suite of Selenium functions enables you to create step-by-step interactions with a webpage and assess the response of a browser to various changes. You can then decide if the response of the browser is in line with what you expect. This post assumes that you do not have prior knowledge of Selenium. However, basic knowledge of front-end concepts like DOM and familiarity with Python is expected. Pre-requisites for running Selenium tests with Python. The easiest way to install Selenium on a Python environment is through the installer pip. While the installation of Selenium makes the functionality available to you, you need additional drivers for it to be able to interface with a chosen web browser. The download links for the drivers are available here: Chrome, Edge, Firefox, and Safari. For the remainder of this tutorial, we will use the Chromedriver. Follow the link for the browser of your choice and download the driver for the compatible version. If you only plan to locally test Selenium, downloading the package and drivers should suffice. However, if you would like to set Selenium up on a remote server, you would additionally need to install the Selenium Server. Selenium Server is written in Java, and you need to have JRE 1.6 or above to install it on your server. It is available on Selenium’s download page. How to run your automated test using Selenium and Python? Once you have completed the pre-requisites section, you are ready to start your first test in Selenium with the Python programming language! 1. First import the webdriver and Keys classes from Selenium. The webdriver class will connect you to a browser’s instance, which we will shortly cover. The Keys class lets you emulate the stroke of keyboard keys, including special keys like “Shift” and “Return”. 2. Next, create an instance of Chrome with the path of the driver that you downloaded through the websites of the respective browser. In this example, we assume that the driver is in the same directory as the Python script that you will execute. If you are testing on your local machine, this opens an instance of Chrome locally. This command lets you perform tests on it until you use the .close() method to end the connection to the browser. In case, you want to try Local Testing using our BrowserStack Automate, check out this documentation. 3. Next, use the .get() method of the driver to load a website. You may also load a local development site as this process is equivalent to opening a window of Chrome on your local machine, typing a URL and hitting Enter. The .get() method not only starts loading a website but also waits for it to render completely before moving on to the next step. 4. Once the page loads successfully, you can use the .title attribute to access the textual title of the webpage. If you wish to check whether the title contains a particular substring, you can use the assert or if statements. For simplicity, let us print the title of the page. The output is the following text – If you are running the test on a Python interpreter, you notice that the Chrome browser window is still active. Also, a message on Chrome states that automated software is controlling it at the moment. 5. Next, let us submit a query in the search bar. First, select the element from the HTML DOM and enter a value into it and submit the form by emulating the Return key press. You can select the element using its CSS class, ID, its name attribute, or even the tag name. If you check the source of the query search bar, you notice that the name attribute of this DOM element is “q”. Therefore, you can use the .find_element_by_name() method as follows to select the element. 6. Once the DOM element is selected, you first need to clear its contents using the .clear() method, enter a string as its value using the .send_keys() method and finally, emulate the press of the Return key using Keys.RETURN . Also read: Want to understand other use cases of SendKeys in Selenium? Check it out. You notice in the window that these actions trigger a change in the URL with the search results in the window. To confirm the current URL of the window, you can use the following command. The following string is displayed – To close the current session, use the .close() method. It also disconnects the link with the browser. In this example, we have looked at the steps involved in running our first test using Selenium and Python. Do note that we kept the window open during all stages of the test, to ensure you knew what went on in the background as you run each command. In a fully automated flow, you will run multiple tests sequentially and hence, may not be able to view each step as they take place. To summarise the discussion, here is your first Selenium test on Python . You may save it in the file selenium_test.py and run python selenium_test.py to run the test. Navigate through HTML DOM Elements. Now that you have successfully run your first test in Selenium with Python, let us look at various options to select DOM elements and interact with them. In the example, we selected the search bar and queried for a string. Let us explore the selection further. Here is the HTML of the search bar. In the example, we used the .find_element_by_name() method, which searches for the attribute name within the input HTML tag. We can also search for this term using other methods. CSS ID: .find_element_by_id(“id-search-field”) DOM Path: .find_element_by_xpath(“//input[@id=’id-search-field’]”) CSS class: .find_element_by_class_name(“search-field”) While the CSS ID is unique to every element by design, you may find multiple results when searching through the class name. Further, when you search through the DOM path of the element, you can be certain of what you are searching for. Did you know: Difference between findElement and findElements ? Find out . Navigate through Windows and Frames. Your may require you to work with multiple windows and frames. Common use cases of working on new windows are social logins and file uploads. The .switch_to_window() method of the driver will help you to change the active window and work on different actions in a new window. The code that switches focus to a new window is: If the value is not stored in the target attribute, you may use a window handle, which uniquely identifies all open windows in your driver. To view a list of all window handles, run the following: Similarly, you can switch focus to a frame within a window through the .switch_to_frame() method. To switch back to the primary window after completing relevant actions, run the following. Note that all actions within this section change the state of the driver and do not return anything. Therefore, we do not store the values in a variable and instead call the methods. Work with Idle Time During a Test. While we have looked at various tests in static web applications, a single-page application may require you to wait for a specific time until you perform an action. There are two types of waits in Selenium: implicit and explicit waits. An explicit wait makes your driver wait for a specific action to be completed (like content load using AJAX). An implicit wait makes the driver wait for a particular time. For an explicit wait, you need to use a try-finally block because it can potentially make your test stuck in the worst-case scenario. Essentially, you instruct the driver to wait for a certain element for a specified time before letting go. First, use the WebDriverWait() function to tell the driver to wait for an amount of five seconds. You then test for a new element to be loaded using the .presence_of_element_located() method of the expected_conditions class, which you can query through By.ID . Want to understand more about ExpectedConditions in Selenium? In an implicit wait, you need to use the .implicitly_wait() method of the driver and supply the number of seconds for the driver to wait. How to integrate Selenium with Python Unit Tests. Let us try to understand how to integrate Selenium tests into Python unit tests. For this purpose, we will use the unit test module in Python. In this example, you need to set up the driver object when initializing the unit test class through the .Chrome() method. In the single test that we demonstrate, the same text is put on the search bar and the resultant change in URL is compared to the URL that was seen earlier. You may additionally write a different test for a different browser and reuse the same functionality. How to run Selenium tests using Python on BrowserStack. To run Selenium on real devices through BrowserStack, you need to register on BrowserStack first. You get 100 minutes of free testing under the free plan, after which you need to subscribe to a monthly plan. On logging in, select “BrowserStack Automate” and set the device-browser combination on which you would like to run a test. You are then shown the sample code to copy over and run from your terminal to run your test. Let us take a moment to see the differences from what we have discussed so far in this article. First, you will notice that the test is conducted on a remote server and not on your local machine. Hence, you are using the .Remote() method to call a specific URL with the settings that you need. Selenium Server is installed on the BrowserStack cloud, which takes care of the initialization of the relevant browser and device for you to test on. Once the driver is initiated, you are familiar with the rest of the commands. Did you know: Difference between Selenium Standalone Server and Selenium Server ? Find out . The following is the output of the code, as expected. BrowserStack allows you to view a video of the test being performed on the device in real- time from your dashboard too. Limitations with Selenium Python tests. While Selenium helps you in automating your tests and saving precious time, it has its limitations. Even with such a robust testing suite, you will often find yourself in an awkward position due to the ever-changing nature of front-end technologies. Here are the top five challenges that one faces when automating the testing process with Selenium. Final Thoughts. In this article, we covered various techniques of automating your cross browser testing process through Selenium using the Python programming language. While we have discussed the nuances of browser support, DOM navigation, waits, and unit tests. Finally, we covered how to perform remote testing on BrowserStack. Even with all the knowledge of how the Selenium framework works, your testing framework is only as robust as the tests you design. Automating the testing process saves a lot of time during the test, so you should ensure that you spend significant time on designing the tests to capture all possible scenarios. It’s always better to catch an error in the testing phase rather than leading to a customer complaint. How to download embedded PDF from webpage using selenium? I tried the code mentioned below but it did not work out. Any help is appreciated. Thanks in advance!! 2 Answers 2. Here You go, description in code: Here is another way to grab the file without clicking/downloading. This method also helps you to download the file to your local machine if your tests are executed in Selenium Grid (remote nodes). Here is how my dom looks like. Not the answer you're looking for? Browse other questions tagged python selenium pdf or ask your own question. Linked. Related. Hot Network Questions. Subscribe to RSS. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. rev 2021.8.4.39914. By clicking “Accept all cookies”, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. selenium 3.141.0. The selenium package is used to automate web browser interaction from Python. Home : http://www.seleniumhq.org Docs : selenium package API Dev : https://github.com/SeleniumHQ/Selenium PyPI : https://pypi.org/project/selenium/ IRC : #selenium channel on freenode. Several browsers/drivers are supported (Firefox, Chrome, Internet Explorer), as well as the Remote protocol. Supported Python Versions. Python 2.7, 3.4+ Installing. If you have pip on your system, you can simply install or upgrade the Python bindings: Alternately, you can download the source distribution from PyPI (e.g. selenium-3.141.0.tar.gz), unarchive it, and run: Note: You may want to consider using virtualenv to create isolated Python environments. Drivers. Selenium requires a driver to interface with the chosen browser. Firefox, for example, requires geckodriver, which needs to be installed before the below examples can be run. Make sure it’s in your PATH , e. g., place it in /usr/bin or /usr/local/bin . Failure to observe this step will give you an error selenium.common.exceptions.WebDriverException: Message: ‘geckodriver’ executable needs to be in PATH. Other supported browsers will have their own drivers available. Links to some of the more popular browser drivers follow. Chrome : https://sites.google.com/a/chromium.org/chromedriver/downloads Edge : https://developer.microsoft.com/en-us/microsoft- edge/tools/webdriver/ Firefox : https://github.com/mozilla/geckodriver/releases Safari : https://webkit.org/blog/6900/webdriver-support-in-safari- 10/ Example 0: open a new Firefox browser load the page at the given URL. Example 1: open a new Firefox browser load the Yahoo homepage search for “seleniumhq” close the browser. Example 2: Selenium WebDriver is often used as a basis for testing web applications. Here is a simple example using Python’s standard unittest library: Selenium Server (optional) For normal WebDriver scripts (non-Remote), the Java server is not needed. However, to use Selenium Webdriver Remote or the legacy Selenium API (Selenium-RC), you need to also run the Selenium server. The server requires a Java Runtime Environment (JRE).