Error with module using Cloud Storage with Python and his tutorial - google-app-engine

Question

I'm trying to test Google Cloud Storage to store images (I need it in an app that I'm developing) and I'm following the Bookshelf App tutorial that they have in his webpage.
I'm using python and the problem is that when I execute the requirementes.txt all packages have been installed fine, but when I try execute the code, I see this error:
...sandbox.py", line 948, in load_module
raise ImportError('No module named %s' % fullname)
ImportError: No module named cryptography.hazmat.bindings._openssl
I have been trying hundred of posibles solutions, reinstalling only the cryptography package, trying to use different versions of the same module, and installing other packages that contains it but anything resolved the problem.
The requirements contains this:
Flask==0.10.1
gcloud==0.9.0
gunicorn==19.4.5
oauth2client==1.5.2
Flask-SQLAlchemy==2.1
PyMySQL==0.7.1
Flask-PyMongo==0.4.0
PyMongo==3.2.1
six==1.10.0
I'm sure that it is a simple error but I don't find the way to solve it.
Any help will be welcome. Thanks.
EDIT:
When I try do this with a python program this work fine:
import os
from gcloud import storage
os.environ['GOOGLE_APPLICATION_CREDENTIALS'] = 'key.json'
client = storage.Client(project='xxxxxxx')
bucket = client.get_bucket('yyyyyyy')
f = open('profile.jpg', 'rb')
blob = bucket.blob(f.name)
blob.upload_from_string(f.read(), 'image/jpeg')
url = blob.public_url
print url
Why I don't can use gcloud library without erros in a GAE app?

Answer 1

It seems you're following the bookshelf tutorial, but according to this line in your stacktrace:
...sandbox.py", line 948, in load_module
It hints that you're using dev_appserver.py to run the code. This isn't necessary for Managed VMs/Flexible unless you're using the compat runtime.
If this is the case, the tutorial provides correct instructions:
$ virtualenv env
$ source env/bin/activate
$ pip install -r requirements.txt
$ python main.py
(If this is not the case, please feel free to comment on this with more details about how you're running your application).