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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def sign(config, s_filename):
 """sign the package"""

    gpg_home = config.get('gpg_dir', '/var/lib/sachannelupdate/gnupg')
    gpg_pass = config.get('gpg_passphrase')
    gpg_keyid = config.get('gpg_keyid')
    gpg = GPG(gnupghome=gpg_home)
    try:
        plaintext = open(s_filename, 'rb')
        signature = gpg.sign_file(
            plaintext, keyid=gpg_keyid, passphrase=gpg_pass, detach=True)
        with open('%s.asc' % s_filename, 'wb') as handle:
            handle.write(str(signature))
    finally:
        if 'plaintext' in locals():
            plaintext.close()