Dictionary usage with Python 3

[Attila_Krasznahorkay]

Hi,

I’ve just run into something that I can’t make heads or tails of…

I’m experimenting with a “new compiler” at the moment. I’ve re-built all of my “externals” and all of my own code with this “new compiler”, and am trying to now use all of it.

The compiler’s setup came with a custom build of Python 3.7.4, so I built ROOT (and all of my own code) against that version of Python.

My problem is that I can’t make the ROOT python module recognise any of my own classes. Even if I explicitly load the library holding a certain dictionary, I still get:

[bash][atspot01]:run > python
Python 3.7.4 (default, Sep 18 2019, 23:00:06) 
[GCC 7.3.0] :: Intel(R) Corporation on linux
Type "help", "copyright", "credits" or "license" for more information.
Intel(R) Distribution for Python is brought to you buy Intel Corporation.
Please check out: https://software.intel.com/en-us/python-distibution
>>> import ROOT
>>> ROOT.gSystem.Load( 'libAsyncEventLoop' )
0
>>> job = ROOT.async.Job()
  File "<stdin>", line 1
    job = ROOT.async.Job()
                   ^
SyntaxError: invalid syntax
>>>

Of course when I build the code against Python 2.7 I don’t see any issue like this. There ROOT correctly auto-loads all necessary dictionaries for me…

[bash][atspot01]:run > python
Python 2.7.15+ (default, Oct  7 2019, 17:39:04) 
[GCC 7.4.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import ROOT
>>> job = ROOT.async.Job()
>>>

Since this is the first time that I’m actually trying to use (Py)ROOT with Python 3 I have no clue where the fault lies. Whether it’s something that this particular Python version is doing incorrectly, something that I messed up with my local ROOT build against that version of Python, or what.

Any ideas would be much appreciated!

Cheers,
Attila

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ROOT Version: 6.18/04
Platform: Ubuntu 18.04
Compiler: It’s a long story…

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[bellenot]

@etejedor will most probably be able to help you, as soon as he’s back

[sbinet]

async is a keyword with Python 3.7.

(got to love non-bwd compatibility changes in Python with minor version bumps…)

>>> import keyword
>>> keyword.kwlist
['False',
 'None',
 'True',
 'and',
 'as',
 'assert',
 'async',
 'await',
[...]
 'try',
 'while',
 'with',
 'yield']

[Attila_Krasznahorkay]

Ahh. That would explain it of course. Thanks Sebastien!