I am using Pyme to interface with GPGME and have had no problems signing / encrypting.  When I try to decrypt, however, it always brings up the prompt for the passphrase despite having set it via a c.set_passphrase_cb callback. Am I doing something wrong?
Add "c.set_armor(1)" before you set the passphrase callback.
Python Pyme: Simple decryption without user interaction