Using Python in Lazarus on Windows/Linux

Intro

I need to make app, cross platform, Win/Linux, which embeds Python engine. I tried Python4Delphi, but it doesn't compile and work on Linux x64. Same app must run on Win and Linux, must use portable Python 3 on Win and system Python 3 on Linux.

Result

Links

• modified Python4Delphi
• app

Work on Ubuntu 14.04 x64

Work on Windows7 x64

Code

P4D

Package "p4dlaz.lpk": delete all refs to units "...Delphi...". (Maybe units aren't needed for Lazarus apps.) Make modifications to PythonEngine.pas, see lines with "//AT". Compile and use package. You must see "Python" tab appeared in component pallette.

Program

Put on form: TPythonEngine, TPythonInputOutput, set such props of PythonEngine:

• AutoLoad=False
• DllName empty
• DllPath empty
• FatalAbort=False
• InitScript="import sys; print('Python', sys.version)"
• IO=PythonInputOutput1
• PyFlags=[pfIgnoreEnvironmentFlag]
• UseLastKnownVersion=False

Write event handlers:

• PythonEngine.AfterInit: must add paths to "sys.path". Must do only for Windows, for portable Python, don't do for Linux. I add paths: dir+'DLLs', dir+'python33.zip', dir+'Py' (dir is ExtractFilePath(Application.ExeName)).

   procedure TfmMain.PythonEngineAfterInit(Sender: TObject);
   var
     SDir, S1, S2, S3: string;
   begin
     {$ifdef windows}
     SDir:= ExtractFilePath(Application.ExeName);
     S1:= SDir + 'DLLs';
     S2:= SDir + 'python33.zip';
     S3:= SDir + 'Py';
     Py_SetSysPath([S1, S2, S3]);
     {$endif}
   end;