Setting up python-crypto (2.6-4) ...
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Cipher/PKCS1_OAEP.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Cipher/CAST.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Cipher/Blowfish.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Cipher/AES.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Cipher/ARC4.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Cipher/DES3.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Cipher/ARC2.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Cipher/PKCS1_v1_5.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Cipher/DES.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Cipher/__init__.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Cipher/blockalgo.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Cipher/XOR.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/pct_warnings.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Util/number.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Util/winrandom.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Util/py3compat.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Util/Counter.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Util/randpool.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Util/RFC1751.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Util/py21compat.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Util/_number_new.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Util/__init__.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Util/asn1.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Hash/SHA384.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Hash/SHA224.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Hash/MD5.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Hash/SHA.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Hash/MD4.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Hash/SHA512.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Hash/hashalgo.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Hash/MD2.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Hash/__init__.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Hash/HMAC.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Hash/SHA256.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/Hash/RIPEMD.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/PublicKey/_slowmath.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/PublicKey/RSA.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/PublicKey/pubkey.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/PublicKey/_RSA.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/PublicKey/ElGamal.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/PublicKey/_DSA.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/PublicKey/__init__.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/PublicKey/DSA.py'
[Errno 21] Is a directory: '/usr/lib/python2.7/dist-packages/Crypto/__init__.py'

Huch? That looks fishy. Why are they directories? Or is there something else wrong in /usr/lib/python2.7/dist-packages? Are you able to install other python- packages?