scrapy-selenium-customdriverinstance 0.0.1

A small example package

Scrapy with selenium

Scrapy middleware to handle javascript pages using selenium.

Installation

$ pip install scrapy-selenium

You should use python>=3.6. You will also need one of the Selenium compatible browsers.

Configuration

1. Add the browser to use, the path to the driver executable, and the arguments to pass to the executable to the scrapy settings:

from shutil import which

SELENIUM_DRIVER_NAME = 'firefox'
SELENIUM_DRIVER_EXECUTABLE_PATH = which('geckodriver')
SELENIUM_DRIVER_ARGUMENTS=['-headless']  # '--headless' if using chrome instead of firefox

Optionally, set the path to the browser executable:

SELENIUM_BROWSER_EXECUTABLE_PATH = which('firefox')

In order to use a remote Selenium driver, specify SELENIUM_COMMAND_EXECUTOR instead of SELENIUM_DRIVER_EXECUTABLE_PATH:

SELENIUM_COMMAND_EXECUTOR = 'http://localhost:4444/wd/hub'

Alternatively, you can omit the SELENIUM_DRIVER_NAME, SELENIUM_DRIVER_EXECUTABLE_PATH and SELENIUM_DRIVER_ARGUMENTS settings and pass a Selenium Webdriver instance to each SeleniumRequest instance at the meta parameter 'driver' key.

2. Add the SeleniumMiddleware to the downloader middlewares:

DOWNLOADER_MIDDLEWARES = {
    'scrapy_selenium.SeleniumMiddleware': 800
}

Usage

Use the scrapy_selenium.SeleniumRequest instead of the scrapy built-in Request like below:

from scrapy_selenium import SeleniumRequest

yield SeleniumRequest(url=url, callback=self.parse_result)

Optionally, you can provide a webdriver instance to the request, in the meta parameter with the key driver:

from scrapy_selenium import SeleniumRequest

yield SeleniumRequest(url=url, callback=self.parse_result, meta={'driver': driver})

Either you have to provide a driver instance or the settings SELENIUM_DRIVER_NAME, SELENIUM_DRIVER_EXECUTABLE_PATH and SELENIUM_DRIVER_ARGUMENTS should be set, so the Selenium middleware instance contains a webdriver instance.

Response

The request will be handled by Selenium, and the callback metod will be called, with a response object with a meta key named driver, containing the selenium driver with the request processed.

def parse_result(self, response):
    print(response.request.meta['driver'].title)

For more information about the available driver methods and attributes, refer to the selenium python documentation

The selector response attribute work as usual (but contains the html processed by the selenium driver).

def parse_result(self, response):
    print(response.selector.xpath('//title/@text'))

Additional arguments

The scrapy_selenium.SeleniumRequest accept 4 additional arguments:

wait_time / wait_until

When used, selenium will perform an Explicit wait before returning the response to the spider.

from selenium.webdriver.common.by import By
from selenium.webdriver.support import expected_conditions as EC

yield SeleniumRequest(
    url=url,
    callback=self.parse_result,
    wait_time=10,
    wait_until=EC.element_to_be_clickable((By.ID, 'someid'))
)

screenshot

When used, selenium will take a screenshot of the page and the binary data of the .png captured will be added to the response meta:

yield SeleniumRequest(
    url=url,
    callback=self.parse_result,
    screenshot=True
)

def parse_result(self, response):
    with open('image.png', 'wb') as image_file:
        image_file.write(response.meta['screenshot'])

script

When used, selenium will execute custom JavaScript code.

yield SeleniumRequest(
    url=url,
    callback=self.parse_result,
    script='window.scrollTo(0, document.body.scrollHeight);',
)