hum,

this part of code is really important, and I am lost (but that's not
really a surprise for me)

if I do :
def
build_dpb(user,password,sql_dialect,role,charset,buffers,force_write,no_reserve,db_key_scope):
params = [str(isc_dpb_version1)]

def addString(codeAsByte, s):
#assert isinstance(codeAsByte,types.IntType) and codeAsByte >= 0
and codeAsByte <= 255
sLen = len(s)
if sLen >= 256:
# Because the length is denoted in the DPB by a single byte.
raise ProgrammingError("Individual component of database"
" parameter buffer is too large. Components must be less"
" than 256 bytes."
)
format = 'ii%ds' % sLen # like 'ii50s' for a 50-byte string
newEntry = struct.pack(format, codeAsByte, sLen, s)
params.append(newEntry.decode())
def addInt(codeAsByte, value):
#assert isinstance(codeAsByte,types.IntType) and codeAsByte >= 0
and codeAsByte <= 255
if not isinstance(value, int) or value < 0 or value > 255:
raise ProgrammingError("The value for an integer DPB code
must be"
" an int or long with a value between 0 and 255."
)
newEntry = struct.pack('ipi', codeAsByte, b'\x01', value)
params.append(newEntry.decode())

if user:
addString(isc_dpb_user_name,user.encode("utf8"))
if password:
addString(isc_dpb_password,password.encode("utf8"))
if role:
addString(isc_dpb_sql_role_name,role.encode("utf8"))
if sql_dialect:
addInt(isc_dpb_sql_dialect,sql_dialect)
if charset:
addString(isc_dpb_lc_ctype, charset.encode("utf8"))
if buffers:
addInt(isc_dpb_num_buffers,buffers)
if force_write:
addInt(isc_dpb_force_write,force_write)
if no_reserve:
addInt(isc_dpb_no_reserve,no_reserve)
if db_key_scope:
addInt(isc_dpb_dbkey_scope,db_key_scope)
return ''.join(params)

then I have a ctype error, of course
ibase.isc_attach_database(_isc_status,len(dsn),dsn,_db_handle,len(dpb),dpb)
ctypes.ArgumentError: argument 6: <class 'TypeError'>: wrong type


so we really need to find how to fix this part of code for Python3

build_dpb in fbcore have to be change
but I don't know how yet :(