Python iterator is empty after performing some action on it

I was trying to do a challenge on codeeval in python3 and got stuck trying to improve my solution. Every time i tried to iterate (or print, or some other action) two times consecutively over the same iterator, the second loop came up empty. Here is a minimal example that produces this behavior, although I tried several different combinations with lists etc. that gave me the same result:

pysftp vs. Paramiko

I have a simple requirement to drop a file on an SFTP server. I have found pysftp and Paramiko libraries that seem to allow me to this and developed a simple application using Paramiko but I can’t find a proper source that compares the two so I can decide which one I can/should use. What are the pros and cons for each?