[rbatchgenerator#6] Difference between TInterpreter::LoadMacro() and TInterpreter::LoadFile()?

Newbie
,
1

ROOT Version: 6.38.04 ( tags/v6-38-04@v6-38-04)
Platform: linuxx8664gcc
Compiler: c++ (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0 std201703

Hello,

TL;DR I wasn’t able to get error code of gInterpreter.LoadMacro() in Python. So I switched to gInterpreter.LoadFile().

C++: LoadMacro(): OK

With Cling, fetching error code of gInterpreter->LoadMacro() seems to work, e.g. with a non-existing file:

15:56 $ date
mar. 02 juin 2026 15:56:54 CEST
(torch) ✔ /.../rbatchgenerator [6-vector-of-vector|…2] 
15:56 $ root
   ------------------------------------------------------------------
  | Welcome to ROOT 6.38.04                        https://root.cern |
  | (c) 1995-2025, The ROOT Team; conception: R. Brun, F. Rademakers |
  | Built for linuxx8664gcc on Apr 27 2026, 12:34:46                 |
  | From tags/v6-38-04@v6-38-04                                      |
  | With c++ (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0 std201703       |
  | Try '.help'/'.?', '.demo', '.license', '.credits', '.quit'/'.q'  |
   ------------------------------------------------------------------

root [0] TInterpreter::EErrorCode error
(TInterpreter::EErrorCode) (TInterpreter::kNoError) : (unsigned int) 0
root [1] gInterpreter->LoadMacro("non-existing", &error)
root [2] error
(TInterpreter::EErrorCode) (TInterpreter::kRecoverable) : (unsigned int) 1
root [3] .q

Python: LoadMacro(): KO?

However, I wasn’t able to get the same result in Python:

15:58 $ python
Python 3.12.3 (main, Mar 23 2026, 19:04:32) [GCC 13.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import ROOT
>>> error = ROOT.TInterpreter.EErrorCode()
>>> error
(TInterpreter::EErrorCode::TInterpreter::EErrorCode) : (unsigned int) 0
>>> ROOT.gInterpreter.LoadMacro("non-existing", error)
>>> error
(TInterpreter::EErrorCode::TInterpreter::EErrorCode) : (unsigned int) 0
>>> exit()

Documentation I found but don’t fully understand:

Python: LoadFile(): OK

As an alternative, gInterpreter.LoadFile() seems to work with Python:

16:12 $ python
Python 3.12.3 (main, Mar 23 2026, 19:04:32) [GCC 13.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import ROOT
>>> ROOT.gInterpreter.LoadFile("non-existing")
1
>>> exit()

Documentation I found but don’t fully understand:

Discussion

  • Could you explain in simple terms the difference between LoadMacro() and LoadFile()?
  • In Python, how can I fetch error with LoadMacro()?

Best regards,