Q:

How to configure ChromeDriver to initiate Chrome browser in Headless mode through Selenium?

I'm working on a python script to web-scrape and have gone down the path of using Chromedriver as one of the packages. I would like this to operate in the background without any pop-up windows. I'm using the option 'headless' on chromedriver and it seems to do the job in terms of not showing the browser window, however, I still see the .exe file running. See the screenshot of what I'm talking about. Screenshot
This is the code I am using to initiate ChromeDriver:
options = webdriver.ChromeOptions()
options.add_experimental_option("excludeSwitches",["ignore-certificate-errors"])
options.add_argument('headless')
options.add_argument('window-size=0x0')
chrome_driver_path = "C:\Python27\Scripts\chromedriver.exe"

Things I've tried to do is alter the window size in the options to 0x0 but I'm not sure that did anything as the .exe file still popped up.
Any ideas of how I can do this?
I am using Python 2.7 FYI

A:

It should look like this:
from selenium import webdriver
from selenium.webdriver.chrome.options import Options

options = Options()
options.add_argument('--headless')
options.add_argument('--disable-gpu')  # Last I checked this was necessary.
driver = webdriver.Chrome(CHROMEDRIVER_PATH, chrome_options=options)

This works for me using Python 3.6, I'm sure it'll work for 2.7 too.
Update 2018-10-26: These days you can just do this:
from selenium import webdriver
from selenium.webdriver.chrome.options import Options

options = Options()
options.headless = True
driver = webdriver.Chrome(CHROMEDRIVER_PATH, chrome_options=options)

A:

Answer update of 13-October-2018
To initiate a google-chrome-headless browsing context using Selenium driven ChromeDriver now you can just set the --headless property to true through an instance of Options() class as follows:

Effective code block:
from selenium import webdriver
from selenium.webdriver.chrome.options import Options

options = Options()
options.headless = True
driver = webdriver.Chrome(options=options, executable_path=r'C:\path\to\chromedriver.exe')
driver.get("http://google.com/")
print ("Headless Chrome Initialized")
driver.quit()

Answer update of 23-April-2018
Invoking google-chrome in headless mode programmatically have become much easier with the availability of the method set_headless(headless=True) as follows :

Documentation :
set_headless(headless=True)
    Sets the headless argument

    Args:
        headless: boolean value indicating to set the headless option

Sample Code :
from selenium import webdriver
from selenium.webdriver.chrome.options import Options

options = Options()
options.set_headless(headless=True)
driver = webdriver.Chrome(options=options, executable_path=r'C:\path\to\chromedriver.exe')
driver.get("http://google.com/")
print ("Headless Chrome Initialized")
driver.quit()

Note : --disable-gpu argument is implemented internally.

Original Answer of Mar 30 '2018
While working with Selenium Client 3.11.x, ChromeDriver v2.38 and Google Chrome v65.0.3325.181 in Headless mode you have to consider the following points :

You need to add the argument --headless to invoke Chrome in headless mode.

For Windows OS systems you need to add the argument --disable-gpu

As per Headless: make --disable-gpu flag unnecessary --disable-gpu flag is not required on Linux Systems and MacOS.

As per SwiftShader fails an assert on Windows in headless mode --disable-gpu flag will become unnecessary on Windows Systems too.

Argument start-maximized is required for a maximized Viewport.

Here is the link to details about Viewport.

You may require to add the argument --no-sandbox to bypass the OS security model.

Effective windows code block :
from selenium import webdriver
from selenium.webdriver.chrome.options import Options

options = Options()
options.add_argument("--headless") # Runs Chrome in headless mode.
options.add_argument('--no-sandbox') # Bypass OS security model
options.add_argument('--disable-gpu')  # applicable to windows os only
options.add_argument('start-maximized') # 
options.add_argument('disable-infobars')
options.add_argument("--disable-extensions")
driver = webdriver.Chrome(chrome_options=options, executable_path=r'C:\path\to\chromedriver.exe')
driver.get("http://google.com/")
print ("Headless Chrome Initialized on Windows OS")

Effective linux code block :
from selenium import webdriver
from selenium.webdriver.chrome.options import Options

options = Options()
options.add_argument("--headless") # Runs Chrome in headless mode.
options.add_argument('--no-sandbox') # # Bypass OS security model
options.add_argument('start-maximized')
options.add_argument('disable-infobars')
options.add_argument("--disable-extensions")
driver = webdriver.Chrome(chrome_options=options, executable_path='/path/to/chromedriver')
driver.get("http://google.com/")
print ("Headless Chrome Initialized on Linux OS")

Outro
How to make firefox headless programmatically in Selenium with python?

tl; dr
Here is the link to the Sandbox story.

A:

The .exe would be running anyway. According to Google - "Run in headless mode, i.e., without a UI or display server dependencies."
Better prepend 2 dashes to command line arguments, i.e. options.add_argument('--headless')
In headless mode, it is also suggested to disable the GPU, i.e. options.add_argument('--disable-gpu')

