Using Python in Lazarus on Windows/Linux
Intro
I need to make app, cross platform, Win/Linux/Mac, which embeds Python engine. I tried Python4Delphi, it doesn't compile and work on Linux x64 and Mac. App must use: portable Python on Win, system Python on Linux, Python installer on Mac.
Resulting repo
Github repo: https://github.com/Alexey-T/Python-for-Lazarus
It has demo, which shows TEdit+TMemo as Python console, to input commands in Edit and show results in Memo. Special allowed first char "=" means to do "print(...)".
Screenshot on Ubuntu 14 x64:
Screenshot on Windows 7 x64:
Screenshot on macOS 10.8:
Code is modified Python4Delphi package. Compile and install the Lazarus package. You will see "Python" tab in IDE component pallette. What is changed since original Python4Delphi:
- deleted all refs to units "..Delphi..", seems units aren't needed for Lazarus apps.
- modifications to PythonEngine.pas, see lines with "//AT".
- added support for macOS, for ex by replacing "$ifdef linux" with "$ifdef unix".
Files on Windows
On Windows you need to copy files to app folder. From "Sublime Text 3" installation for win, take Python files and copy them to app folder:
- python33.dll
- msvcr100.dll
- python33.zip
- .pyd files, to folder DLLs
Manifest on Windows: "appname.exe.manifest":
<?xml version="1.0" encoding="UTF-8" standalone="yes"?> <assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0"> <noInheritable/> <assemblyIdentity type="win32" name="DelphiApplication" version="1.0.0.0" processorArchitecture="*"/> <dependency> <dependentAssembly> <assemblyIdentity type='win32' name='Microsoft.Windows.Common-Controls' version='6.0.0.0' processorArchitecture='*' publicKeyToken='6595b64144ccf1df' language='*' /> </dependentAssembly> </dependency> <trustInfo xmlns="urn:schemas-microsoft-com:asm.v3"> <security> <requestedPrivileges> <requestedExecutionLevel level='asInvoker' uiAccess='false' /> </requestedPrivileges> </security> </trustInfo> </assembly>
Files on MacOS
OSX 10.8 doesn't have Python. User needs to install official Py 3.4 pack.
Full path to library must be set in code, I could not load it w/out path. (Maybe I can read some env-var, I didn't try.)
Code
Form
Put on form:
- TPythonEngine
- TPythonInputOutput
- TCombobox (edConsole)
- TMemo (memoConsole)
Properties of PythonEngine:
- AutoLoad=False
- DllName empty
- DllPath empty
- FatalAbort=False
- InitScript="import sys; print('Python', sys.version)"
- IO=PythonInputOutput1
- PyFlags=[pfIgnoreEnvironmentFlag]
- UseLastKnownVersion=False
Event handlers
- PythonEngine.OnAfterInit: must set "sys.path" for Win (remember, we use portable py for Win).
procedure TfmMain.PythonEngineAfterInit(Sender: TObject);
var
dir: string;
begin
{$ifdef windows}
dir:= ExtractFilePath(Application.ExeName);
Py_SetSysPath([
dir + 'DLLs',
dir + 'python33.zip'
]);
{$endif}
end;
procedure Py_SetSysPath(const Dirs: array of string);
var
Str: string;
i: Integer;
begin
Str:= '';
for i:= 0 to Length(Dirs)-1 do
Str:= Str + 'r"' + Dirs[i] + '"' + ',';
Str:= Format('sys.path = [%s]', [Str]);
GetPythonEngine.ExecString(Str);
end;
- PythonInputOutput.OnSendData, OnSendUniData:
procedure TfmMain.PythonInputOutput1SendData(Sender: TObject;
const Data: AnsiString);
begin
memoConsole.Lines.Add(Data);
end;
procedure TfmMain.PythonInputOutput1SendUniData(Sender: TObject;
const Data: UnicodeString);
begin
memoConsole.Lines.Add(Data);
end;
- edConsole.OnKeyPress:
procedure TfmMain.edConsoleKeyPress(Sender: TObject; var Key: char);
var
Str: string;
begin
if Key=#13 then
begin
Str:= edConsole.Text;
//support entering "=some cmd"
if (Str<>'') and (Str[1]='=') then
Str:= 'print('+Copy(Str, 2, MaxInt) + ')';
memoConsole.Lines.Add('>>> '+Str);
edConsole.Text:= '';
edConsole.Items.Insert(0, Str);
try
GetPythonEngine.ExecString(Str);
except
end;
end;
end;
- main form OnCreate:
const
cPyLibraryWindows = 'python33.dll';
cPyLibraryLinux = 'libpython3.4m.so.1.0';
cPyLibraryMac = '/Library/Frameworks/Python.framework/Versions/3.4/lib/libpython3.4.dylib';
procedure TfmMain.FormCreate(Sender: TObject);
var
S: string;
begin
S:=
{$ifdef windows} cPyLibraryWindows {$endif}
{$ifdef linux} cPyLibraryLinux {$endif}
{$ifdef darwin} cPyLibraryMac {$endif} ;
PythonEngine.DllPath:= ExtractFileDir(S);
PythonEngine.DllName:= ExtractFileName(S);
PythonEngine.LoadDll;
end;