Inno Setup - Get Data from CreateInputDirPage for putting files in folder selected

Question

I have written a script that is supposed to install in Program Files folder and add a file to another folder chosen

[Code]
var
  OutputProgressWizardPage: TOutputProgressWizardPage;
  OutputProgressWizardPageAfterID: Integer;
  PythonHome: String;
procedure InitializeWizard;
var
  //InputQueryWizardPage: TInputQueryWizardPage;
  //InputOptionWizardPage: TInputOptionWizardPage;
  InputDirWizardPage: TInputDirWizardPage;
  PrimaryServerPage: TInputQueryWizardPage;
  InputFileWizardPage: TInputFileWizardPage;
  OutputMsgWizardPage: TOutputMsgWizardPage;
  OutputMsgMemoWizardPage: TOutputMsgMemoWizardPage;
  AfterID: Integer;
begin
  //WizardForm.PasswordEdit.Text := '{#Password}';

  AfterID := wpSelectTasks;

  //AfterID := CreateCustomPage(AfterID, 'CreateCustomPage', 'ADescription').ID;

  //InputQueryWizardPage := CreateInputQueryPage(AfterID, 'CreateInputQueryPage', 'ADescription', 'ASubCaption');
  //InputQueryWizardPage.Add('&APrompt:', False);
  //AfterID := InputQueryWizardPage.ID;

  //InputOptionWizardPage := CreateInputOptionPage(AfterID, 'CreateInputOptionPage', 'ADescription', 'ASubCaption', False, False);
  //InputOptionWizardPage.Add('&AOption');
  //AfterID := InputOptionWizardPage.ID;

  InputDirWizardPage := CreateInputDirPage(AfterID, 'Choose Python Home Folder', '', '', False, '');
  InputDirWizardPage.Add('&Location of Python Home:');
  InputDirWizardPage.Values[0] := 'C:\Python27';
  AfterID := InputDirWizardPage.ID;
  ...
  ...
 end

function NextButtonClick(CurPageID: Integer): Boolean;
var
  Position, Max: Integer;
begin
  if CurPageID = OutputProgressWizardPageAfterID then begin
    try
      Max := 25;
      for Position := 0 to Max do begin
        OutputProgressWizardPage.SetProgress(Position, Max);
        if Position = 0 then
          OutputProgressWizardPage.Show;
        Sleep(2000 div Max);
      end;
    finally
      OutputProgressWizardPage.Hide;
    end;
  end;
  Result := True;
end;

function PrepareToInstall(var NeedsRestart: Boolean): String;
begin
  if SuppressibleMsgBox('Do you want to stop Setup at the Preparing To Install wizard page?', mbConfirmation, MB_YESNO, IDNO) = IDYES then
    Result := 'Stopped by user';
end;

function GetPythonHome(Param: String): string;
begin
  Result := PythonHome;
end;

No matter what I change as the folder in The Installer Page that asks me to choose the Python Folder, It always picks to the default suggestion - C:\Python27.

How do I overcome this? What change must I make? There seems to be no manual online for Inno Setup Scripting as well. Please help me

The [Files] section -

[Files]
  Source: "C:\Users\pnarendr\Desktop\API_DAST\*"; DestDir: "{app}"; Flags: ignoreversion recursesubdirs createallsubdirs
  ; NOTE: Don't use "Flags: ignoreversion" on any shared system files
  **; Not taking in changed PythonHome**
  Source: "C:\Users\pnarendr\Desktop\output.log"; DestDir: "{code:GetPythonHome}";