Starting With Selenium's Python Package (Installation)

  
We have a YAML file to setup our conda environment. The file 'selenium.yml' has contents:

name: selenium
channels:
  - conda-forge
  - defaults
dependencies:
  - selenium
  - jupyterlab
  - ipykernel 

To setup the environment, we run the command:

(base) CMD> conda env create -f selenium.yml 

(selenium) CMD> conda activate selenium 

After that, if we want to see which all packages got installed, we run the command:

(selenium) CMD> conda env export 

Next, we setup a kernel from this environment:

(selenium) CMD> python -m ipykernel install --user --name selenium 
Installed kernelspec selenium in C:\Users\Ashish Jain\AppData\Roaming\jupyter\kernels\selenium 

To view the list of kernels:

(selenium) CMD> jupyter kernelspec list 
Available kernels:
  selenium              C:\Users\Ashish Jain\AppData\Roaming\jupyter\kernels\selenium
  python3               E:\programfiles\Anaconda3\envs\selenium\share\jupyter\kernels\python3 
  ... 
  
A basic piece of code would start the browser. We have tried and tested it for Chrome and Firefox. To do this, we need the web driver file or we get the following exception:

CODE:

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

driver = webdriver.Chrome()  

ERROR:

----------------------------------------------------------------------
FileNotFoundError                         Traceback (most recent call last)
E:\programfiles\Anaconda3\envs\selenium\lib\site-packages\selenium\webdriver\common\service.py in start(self)
     71             cmd.extend(self.command_line_args())
---> 72             self.process = subprocess.Popen(cmd, env=self.env,
     73                                             close_fds=platform.system() != 'Windows',

E:\programfiles\Anaconda3\envs\selenium\lib\subprocess.py in __init__(self, args, bufsize, executable, stdin, stdout, stderr, preexec_fn, close_fds, shell, cwd, env, universal_newlines, startupinfo, creationflags, restore_signals, start_new_session, pass_fds, encoding, errors, text)
    853 
--> 854             self._execute_child(args, executable, preexec_fn, close_fds,
    855                                 pass_fds, cwd, env,

E:\programfiles\Anaconda3\envs\selenium\lib\subprocess.py in _execute_child(self, args, executable, preexec_fn, close_fds, pass_fds, cwd, env, startupinfo, creationflags, shell, p2cread, p2cwrite, c2pread, c2pwrite, errread, errwrite, unused_restore_signals, unused_start_new_session)
   1306             try:
-> 1307                 hp, ht, pid, tid = _winapi.CreateProcess(executable, args,
   1308                                          # no special security

FileNotFoundError: [WinError 2] The system cannot find the file specified

During handling of the above exception, another exception occurred:

WebDriverException                        Traceback (most recent call last)
...
WebDriverException: Message: 'chromedriver' executable needs to be in PATH. Please see https://sites.google.com/a/chromium.org/chromedriver/home 

We got the file from here: chromedriver.storage.googleapis.com For v86 

chromedriver_win32.zip ---> chromedriver.exe

Error for WebDriver and Browser version mismatch:

SessionNotCreatedException: Message: session not created: This version of ChromeDriver only supports Chrome version 86
Current browser version is 85.0.4183.102 with binary path C:\Program Files (x86)\Google\Chrome\Application\chrome.exe 

Download from here for Chrome v85: chromedriver.storage.googleapis.com For v85 

One point to note about ChromeDriver as in September 2020:

ChromeDriver only supports characters in the BMP (Basic Multilingual Plane) is a known issue with Chromium team as ChromeDriver still doesn't support characters with a Unicode after FFFF. Hence it is impossible to send any character beyond FFFF via ChromeDriver. As a result any attempt to send SMP (Supplementary Multilingual Plane) characters (e.g. CJK, Emojis, Symbols, etc) raises the error. 

While Firefox supports Emoji's sent via 'send_keys()' method. 

As of Unicode 13.0, the SMP comprises the following 134 blocks: Archaic Greek and Other Left-to-right scripts: Linear B Syllabary (10000–1007F) Linear B Ideograms (10080–100FF). 

~ ~ ~ ~ ~

If you working with Firefox browser, you need the Gecko WebDriver available at the Windows 'PATH' variable.

Without WebDriver file:
	FileNotFoundError: [WinError 2] The system cannot find the file specified
	WebDriverException: Message: 'geckodriver' executable needs to be in PATH. 

Download Gecko driver from here: GitHub Repo of Mozilla 

The statement to launch the web browser will be: 

driver = webdriver.Firefox()  

By default, browsers open in a partial size window. To maximize the window: 

driver.maximize_window() 

Now, we open a link: driver.get("http://survival8.blogspot.com/")