How to use the pysodium.crypto_sign_keypair function in pysodium

def test_crypto_sign_open(self):
        pk, sk = pysodium.crypto_sign_keypair()
        signed = pysodium.crypto_sign(b'howdy', sk)
        changed = signed[:pysodium.crypto_sign_BYTES] + b'0' + signed[pysodium.crypto_sign_BYTES + 1:]
        pysodium.crypto_sign_open(signed, pk)
        self.assertRaises(ValueError, pysodium.crypto_sign_open, changed, pk)

def test_crypto_sign_sk_to_pk(self):
        pk, sk = pysodium.crypto_sign_keypair()
        pk2 = pysodium.crypto_sign_sk_to_pk(sk)
        self.assertEqual(pk, pk2)

log.info('updating subrepo')
    SubRepo.pull()

    log.info('registering new team: %s' % team_name)
    team = Team(name=team_name)

    if team.exists():
        log.fail('team is already registered')
        return False

    log.info('generating encryption keypair')
    crypt_pk, crypt_sk = pysodium.crypto_box_keypair()

    log.info('generating signature keypair')
    sign_pk, sign_sk = pysodium.crypto_sign_keypair()

    team.update({'countries': countries,
                 'crypt_pk': crypt_pk,
                 'sign_pk': sign_pk})
    team.validate()
    team.save()

    SubRepo.push(commit_message='Register team %s' % team_name)
    log.success('team %s added successfully' % team_name)

    write_team_secrets(team.id, crypt_sk, sign_sk)

    return True

def getkey(keydir):
  datadir = os.path.expanduser(keydir)
  try:
    with open(datadir+'server-key', 'rb') as fd:
      key = fd.read()
    return key
  except FileNotFoundError:
    print("no server key found, generating...")
    if not os.path.exists(datadir):
      os.mkdir(datadir,0o700)
    pk, sk = pysodium.crypto_sign_keypair()
    with open(datadir+'server-key','wb') as fd:
      os.fchmod(fd.fileno(),0o600)
      fd.write(sk)
    with open(datadir+'server-key.pub','wb') as fd:
      fd.write(pk)
    print("please share `%s` with all clients"  % (datadir+'server-key.pub'))
    return sk

def getkey(datadir):
  datadir = os.path.expanduser(datadir)
  try:
    fd = open(datadir+'key', 'rb')
    key = fd.read()
    fd.close()
    return key
  except FileNotFoundError:
    if not os.path.exists(datadir):
      os.mkdir(datadir,0o700)
    pk, sk = pysodium.crypto_sign_keypair()
    with open(datadir+'key','wb') as fd:
      os.fchmod(fd.fileno(),0o600)
      fd.write(sk)
    return sk

def create(self):
        self.created = datetime.datetime.utcnow()
        self.valid = datetime.datetime.utcnow() + datetime.timedelta(days=365)
        self.mp, self.ms = nacl.crypto_sign_keypair()
        self.sp, self.ss = nacl.crypto_sign_keypair()
        self.cp, self.cs = nacl.crypto_box_keypair()
        self.save()

def getkey(self):
    datadir = os.path.expanduser(self.datadir)
    try:
      fd = open(datadir+'key', 'rb')
      key = fd.read()
      fd.close()
      return key
    except FileNotFoundError:
      if not os.path.exists(datadir):
        os.mkdir(datadir,0o700)
      pk, sk = pysodium.crypto_sign_keypair()
      with open(datadir+'key','wb') as fd:
        os.fchmod(fd.fileno(),0o600)
        fd.write(sk)
      return sk