Script to add a file to dropzone via Selenium... from Python

dropzone_selenium.py

def addFileToDropzone(self, driver, css_selector, name, content):
  """
  Trigger a file add with `name` and `content` to Dropzone element at `css_selector`.
  """
  script = """
var dropzone_instance = Dropzone.forElement(css_selector)
var new_file = new File(['%s'], '%s', {type: 'application/octet-binary'})
dropzone_instance.addFile(new_file)
""" % (content, name)
  driver.execute_script(script)


# Use it like
self.addFileToDropzone('z-test.txt', b'file-content-here')

Does content need base64 encoding?

nope: https://developer.mozilla.org/en-US/docs/Web/API/File/File
file content encoded as utf8