如何在谷歌云上安装ortools库

我在使用命令 pip install -t lib/ ortools ,图书馆 ortools 已安装到 lib/ 文件夹但当我在Google App Engine上部署包含该库的Flask项目时,我遇到了以下错误:

(/base/alloc/tmpfs/dynamic_runtimes/python27g/931d17f05408b3ef/python27/python27_lib/versions/1/google/appengine/runtime/wsgi.py:263)
Traceback (most recent call last):
  File "/base/alloc/tmpfs/dynamic_runtimes/python27g/931d17f05408b3ef/python27/python27_lib/versions/1/google/appengine/runtime/wsgi.py", line 240, in Handle
    handler = _config_handle.add_wsgi_middleware(self._LoadHandler())
  File "/base/alloc/tmpfs/dynamic_runtimes/python27g/931d17f05408b3ef/python27/python27_lib/versions/1/google/appengine/runtime/wsgi.py", line 299, in _LoadHandler
    handler, path, err = LoadObject(self._handler)
  File "/base/alloc/tmpfs/dynamic_runtimes/python27g/931d17f05408b3ef/python27/python27_lib/versions/1/google/appengine/runtime/wsgi.py", line 85, in LoadObject
    obj = __import__(path[0])
  File "/base/data/home/apps/b~cidy-1539116366694/20190316t002011.416796594015344313/main.py", line 5, in <module>
    from ortools.constraint_solver import pywrapcp
  File "/base/data/home/apps/b~cidy-1539116366694/20190316t002011.416796594015344313/lib/ortools/constraint_solver/pywrapcp.py", line 17, in <module>
    _pywrapcp = swig_import_helper()
  File "/base/data/home/apps/b~cidy-1539116366694/20190316t002011.416796594015344313/lib/ortools/constraint_solver/pywrapcp.py", line 16, in swig_import_helper
    return importlib.import_module('_pywrapcp')
  File "/base/alloc/tmpfs/dynamic_runtimes/python27g/931d17f05408b3ef/python27/python27_dist/lib/python2.7/importlib/__init__.py", line 37, in import_module
    __import__(name)
ImportError: No module named _pywrapcp