When I try to run app.py (Python 3.3, PyCrypto 2.6) my virtualenv keeps returning the error listed above. My import statement is just from Crypto.Cipher import AES
from Crypto.Cipher import AES
For CentOS 7.4 I first installed pip and then pycrypto using pip:
> sudo yum -y install python-pip > sudo python -m pip install pycrypto