not able to import wit api on google app engine

[ashishietcs]

I have developed an chatbot which is expected to communicate with wit.ai app. When i execute in standalone, i am able to load wit client and can communicate, but once i upload app on app server, its giving me below error :

Traceback (most recent call last):
File "/google/google-cloud-sdk/platform/google_appengine/google/appengine/runtime/wsgi.py", line 240, in Handle
handler = _config_handle.add_wsgi_middleware(self._LoadHandler())
File "/google/google-cloud-sdk/platform/google_appengine/google/appengine/runtime/wsgi.py", line 299, in _LoadHandler
handler, path, err = LoadObject(self._handler)
File "/google/google-cloud-sdk/platform/google_appengine/google/appengine/runtime/wsgi.py", line 85, in LoadObject
obj = import(path[0])
File "/home/ashishietcs/src/fbbot-175613/python_gae_quickstart-2017-08-02-18-40/appengine/standard/hello_world/main.py", line 22, in
from wit import Wit
File "/home/ashishietcs/src/fbbot-175613/python_gae_quickstart-2017-08-02-18-40/appengine/standard/hello_world/lib/wit/init.py", line 9, in
from .wit import Wit
File "/home/ashishietcs/src/fbbot-175613/python_gae_quickstart-2017-08-02-18-40/appengine/standard/hello_world/lib/wit/wit.py", line 12, in
from prompt_toolkit import prompt
File "/home/ashishietcs/src/fbbot-175613/python_gae_quickstart-2017-08-02-18-40/appengine/standard/hello_world/lib/prompt_toolkit/init.py", line 16, in
from .interface import CommandLineInterface
File "/home/ashishietcs/src/fbbot-175613/python_gae_quickstart-2017-08-02-18-40/appengine/standard/hello_world/lib/prompt_toolkit/interface.py", line 17, in
from subprocess import Popen
ImportError: cannot import name Popen