Are there any implementations of SSH in pure python? Preferably open source?
I'm specifically looking for a client, not server.
Try paramiko.
There is no pure Python library for SSH. paramiko is not pure python, because it doesn't work without pyCrypto dongle. It may carry a pure Python implementation of SSH protocol, but it is not usable as a pure Python library - you still need to install binary pyCrypto extension compiled for your platform, and there is no replacement.