GPG Signatue with python3-gpgme

gpg_sign.py

#!/usr/bin/python3                                                                                                                    

import io
import gpgme


def sign(filename):
    context = gpgme.Context()
    context.armor = True
    context.signers = tuple(i for i in context.keylist() if i.can_sign)
    signature = io.BytesIO()
    with open(filename, "rb") as f:
        context.sign(f, signature, gpgme.SIG_MODE_DETACH)
    return signature.getvalue().decode('ascii')