[HTCondor-devel] HTCondor Python Bindings: propose to implement via pybind11 instead of Boost?

[Todd Tannenbaum <tannenba@xxxxxxxxxxx>]

Hi all,

Currently our increasingly popular HTCondor python bindings are 
implemented via Boost.Python.  Now that all HTCondor supported platforms 
have C++11-compatible compilers, I propose we consider implementing our 
bindings via pybind11 [see below for description] instead.  Boost.Python 
is about the only significant thing we use Boost for these days.... 
moving to pybind11 would allow us to eject Boost.  We need to do some 
investigative work, but I think most of our existing Boost.Python 
binding code could be moved over with mostly superficial syntactical 
changes.  Of course we should maintain API compatibility.
pybind11 was written as more or less a replacement for Boost.Python, so 
I think it should do well for the bindings, but I am not sure if the 
embedded Python interpreter for ClassAd function extensions uses Boost 
or not.
Thoughts? Comments?

regards,
Todd

What is pybind11 ?

From https://github.com/pybind/pybind11 :

Think of pybind11 as a tiny self-contained version of Boost.Python with 
everything stripped away that isn't relevant for binding generation. 
Without comments, the core header files only require ~4K lines of code 
and depend on Python (2.7 or 3.x, or PyPy2.7 >= 5.7) and the C++ 
standard library.
And pybind11 actually has decent, complete, organized documentation. It 
looks to have pretty active, wide, and growing support (although I would 
want to confirm that at least a few other major projects are using it 
today).
Everything for pybind11 is contained in just a few header files; there 
is no need to link against any additional libraries!
This compact implementation was possible thanks to some of the new C++11 
language features (specifically: tuples, lambda functions and variadic 
templates). Since its creation, this library has grown beyond 
Boost.Python in many ways, leading to dramatically simpler binding code 
in many common situations.

--
Todd Tannenbaum <tannenba@xxxxxxxxxxx> University of Wisconsin-Madison
Center for High Throughput Computing   Department of Computer Sciences
HTCondor Technical Lead                1210 W. Dayton St. Rm #4257
Phone: (608) 263-7132                  Madison, WI 53706-1685