Selenium-based harness that dynamically evaluates code to allow exploring web automation without re-running the driver

dyncode_wiki.py

# Copyright 2021 Google LLC.
# SPDX-License-Identifier: Apache-2.0
search_input = driver.find_element_by_xpath("//input[@id='searchInput']")
search_input.clear()
search_input.send_keys('George Washington')
submit_button = driver.find_element_by_xpath("//button[@type='submit']")
submit_button.click()

explore_wiki.py

# Copyright 2021 Google LLC.
# SPDX-License-Identifier: Apache-2.0
import pathlib
import time
from selenium import webdriver

# Keep track of the dynamic file's last modified time.
last_modified_time = 0

# Initialize the Chrome driver - needs to be in PATH.
# To download the driver, visit https://chromedriver.chromium.org/downloads
driver = webdriver.Chrome()

# Navigate to Wikipedia
driver.get('https://www.wikipedia.org/')


while True:
  # Sleep for 100ms to avoid pegging the CPU
  time.sleep(100 / 1000)

  # Check for the presence of the file containing dynamic code.
  fname = pathlib.Path('dyncode_wiki.py')
  if not fname.exists():
    continue
  modified_time = fname.stat().st_mtime
  if last_modified_time != modified_time:
    # The heuristic assumes that if the file's modified time has changed,
    # it should be re-executed. Note this will always execute at least once
    # since last_modified_time is initialized to 0. If this is not a desirable
    # behavior, add a check for that: "and last_modified_time != 0".
    # Alternatively, a more sophisticated approach would rely on an md5 hash
    # of the file to only re-run changes if the contents actually changed.
    print('dyncode changed, evaluating...')
    last_modified_time = modified_time
    with open('dyncode_wiki.py') as f:
      try:
        exec(f.read())
      except Exception as e:
        print('Error evaluation code: %s' % e)