ImportError: cannot import name which

I have used which in my settings as:

#selenium

from shutil import which

SELENIUM_DRIVER_NAME = 'chrome'

SELENIUM_DRIVER_EXECUTABLE_PATH = which('chromedriver')

SELENIUM_DRIVER_ARGUMENTS=['-headless']   

requirements.txt file

guppy==0.1.10

selenium>=3.9.0

scrapy-selenium==0.0.7

dependencies on scrapinghub.yml

project: 434717

requirements:

  file: requirements.txt

I got error:

 File "/usr/local/lib/python2.7/site-packages/sh_scrapy/settings.py", line 172, in _populate_settings_base

    settings = get_project_settings().copy()

  File "/usr/local/lib/python2.7/site-packages/scrapy/utils/project.py", line 68, in get_project_settings

    settings.setmodule(settings_module_path, priority='project')

  File "/usr/local/lib/python2.7/site-packages/scrapy/settings/__init__.py", line 288, in setmodule

    module = import_module(module)

  File "/usr/local/lib/python2.7/importlib/__init__.py", line 37, in import_module

    __import__(name)

  File "/app/__main__.egg/andorra/settings.py", line 94, in <module>

ImportError: cannot import name which

{"message": "shub-image-info exit code: 1", "details": null, "error": "image_info_error"}

{"status": "error", "message": "Internal error"}