Free components that wrap up Python into Delphi and Lazarus (FPC)

Python 2 has reached the end of its life, and we can assume that most of the users will have installed python 3. Most of the demos use python 2 print statements and some may use other python 2 idioms.

To facilitate experimentation and learning with the demos they should be converted to python 3.

Also all forms should be changed to text format and the old application icon replaced with the default icon.

I use this fork https://github.com/alexey-t/python-for-lazarus In the folder demo_lazarus I have a demo, which shows the problem. I cannot test this on Delphi (no Delphi here, I use Linux Ubuntu 18.x x64, Python 3.7).

• i run the demo
• demo provides Py module "demo" with function "s1". So i test it.
• in demo console, i enter

import demo
=demo.s1()

and have this error.

This is from Unicode string with high values:

function Py_s1(Self, Args : PPyObject): PPyObject; cdecl;
const
  S0: string = 'begin.𠏽𠏽𠏽𠏽𠏽.end';
begin
  with GetPythonEngine do
    Result:= PyString_FromString(PChar(S0));
end;

Can you repro this on Delphi?

The PyNumberMethods record was designed for Python 2.x and still contains nb_divide, nb_coerce, nb_oct, nb_hex and nb_inplace_divide. On the other hand, it lacks nb_index, nb_matrix_multiply and nb_inplace_matrix_multiply. Also, nb_nonzero was renamed as nb_bool and nb_long as nb_reserved. Finally, it has a typo for nb_substract, which should read nb_subtract.

As a result, for Python 3.x e.g. TPythonType_NbPower() will be called when TPythonType_NbNegative() is intended.

Windows10 Delphi Xe2 update 4 libarary path is added while installation Python_D150.bpl IDE raise Error: [DCC Error] WrapDelphi.pas(2789): E2003 Undeclared identifier: 'TypeData' and point to Error line: WarpDelphi.pas line 278: if (RttiParam.ParamType = nil) or (RttiParam.ParamType.Handle = nil) or (RttiParam.ParamType.Handle.TypeData = nil) then Exit;

I check out the Unit Sytem.Typinfo found a Strange place:

PPTypeInfo = ^PTypeInfo; PTypeInfo = ^TTypeInfo; TTypeInfo = record Kind: TTypeKind; Name: ShortString; {TypeData: TTypeData} end;

the TypeData section is be marked with a curly bracket in Delphi Xe2 !!! I'm not sure if it makes trouble.

I tested code at Ubuntu 19.04 with Python 3.7 and library

/usr/lib/x86_64-linux-gnu/libpython3.7m.so

I changed PythonEngine.pas file to

{$IFDEF _so_files}
  PYTHON_KNOWN_VERSIONS: array[1..8] of TPythonVersionProp =
    (
    (DllName: 'libpython2.7.so'; RegVersion: '2.7'; APIVersion: 1013),
    (DllName: 'libpython3.2.so'; RegVersion: '3.2'; APIVersion: 1013),
    (DllName: 'libpython3.3.so'; RegVersion: '3.3'; APIVersion: 1013),
    (DllName: 'libpython3.4.so'; RegVersion: '3.4'; APIVersion: 1013),
    (DllName: 'libpython3.5.so'; RegVersion: '3.5'; APIVersion: 1013),
    (DllName: 'libpython3.6.so'; RegVersion: '3.6'; APIVersion: 1013),
    (DllName: 'libpython3.7m.so'; RegVersion: '3.7'; APIVersion: 1013),
    (DllName: 'libpython3.8.so'; RegVersion: '3.8'; APIVersion: 1013)
    ); 

Then the python3.7 was recognized but at least not correctly initialized. at line 3057

      // set the argv list of the sys module with the application arguments
      PySys_SetArgv3000( argc + 1, wargv );

With error message:

Project Project1 raised exception class 'External: SIGABRT'. In file '../sysdeps/unix/sysv/linux/raise.c' at line 50

Currently is recognized only Python 2.7. Maybe you will know how to fix it.

I sync'ed this unit (in python4lazarus) and now CudaText ARM64 don't work. it shows py error on start. ValueError: module functions cannot set METH_CLASS or METH_STATIC

I am comparing the new unit with old one (in Python4Lazarus before sync with you). old unit did not have all variants of function GetCallBack. attached this old unit. MethodCallBack.zip

can you please make sure FPC ARM64 works now?

My device: Raspberry Pi-3, OS: Manjaro ARM.

Hello,

I hope I am in the right place for this question. I apologize if I should be asking this somewhere else. I did post this question on the general Lazarus forum but did not get any feedback.

I am using Python for Lazarus in an application to communicate with a few different lab instruments.

I have a Lazarus application that was running well using the NI-Visa library for python. It suddenly stopped working and is now throwing an error:

AttributeError: module 'visa' has no attribute 'ResourceManager'

The odd part is that the same python code runs fine from IDLE or python directly? I am struggling to find any information on how P4L or P4D interacts with python and where this problem could be coming from. I would think they would use the same python module?

I did get some good feedback from python visa forum but I think the visa and python side check out as ok because it is running in python itself. This seems to be something specific to the Lazarus side?

Simple python script that returns error: import visa

from ThorlabsPM100 import ThorlabsPM100 rm = visa.ResourceManager()

Other python scripts seem to run fine from the same Lazarus application.

Any information would be greatly appreciated.

Downloaded latest files from github. Added library path to source.Tried installing on newly installed delphi 10.4 . Build fails because cannot find Pythonguiinputoutput.pas which is in the vcl subfolder. move this file to the source folder and remove vcl prefix. then it fails on not finding designide. add the path to that in library path. delphi then cant find bpl and keeps coming b up with more errors.

Using Lazarus Trunk and FPC 3.2 on Intel MacOS, I am unable to install p4dlaz.lpk.

1. Package fails to compile:

PythonEngine.pas(2861,16) Error: Incompatible types: got "TThreadID" expected "NativeInt"

2. lpk refers to a file that does not exist:

DoOpenDl loop for all PYTHON_KNOWN_VERSIONS defined versions. But if the version is not found then inherited is called with an empty name which causes AV. Inherited should be called only if UseLastKnownVersion is false.

`procedure TPythonEngine.DoOpenDll(const aDllName : string); var i : Integer; begin if UseLastKnownVersion then for i:= Integer(COMPILED_FOR_PYTHON_VERSION_INDEX) downto 1 do begin RegVersion := PYTHON_KNOWN_VERSIONS[i].RegVersion; inherited DoOpenDll(PYTHON_KNOWN_VERSIONS[i].DllName); if IsHandleValid then begin DllName := PYTHON_KNOWN_VERSIONS[i].DllName; APIVersion := PYTHON_KNOWN_VERSIONS[i].APIVersion; Exit; end; end else begin RegVersion := SysVersionFromDLLName(aDllName); inherited; <--- HERE end; end;'

Installation failure - "Can't load package Python_D$(Auto).bpl The system cannot find the file specified" - - Python_D.dprog loaded in Delphi 10.4. Installation documentation too vague to check that I have the correct setup. Using Anaconda3 installation.

Under some circumstances (sorry, I don't have minimal code to reproduce the error) named parameters in VarPyth not cleared between function calls, and function called without named parameters may recieve parameters from previous call with named parameters. Condition check in line 1091 of VarPyth.pas seems to be excessive; in my case commenting it out solved the problem: {if CallDesc^.NamedArgCount > 0 then }GetNamedParams;