silenced after commit 466e5825

silenced after commit 466e5825

Use the generic PyROOT_PyUnicode_FromString function, which is
implemented differently in Py2 and Py3 and in both cases will
produce a Python string.

In Python3, if an error is set (e.g. because we tried to get an
attribute that does not exist from an object), any subsequent
get attribute operation will fail, even if the attribute is
present. Clearing the error after the first (failed) attribute
get solves the problem.

When instantiating a template based on the types of the arguments,
a Python float should be mapped to a C++ double.

After the changes proposed by PR#3858, TClingMethodInfo does not
iterate over instantiated templates anymore. This requires
changes in PyROOT, since GetListOfMethods will not return those
instantiations.

Instead of relying on the instantiations for the lookup of a
given function/method to succeed, the list of function templates
needs to be checked too and create a TemplateProxy if necessary.

The new cmake option `dataframe` enables building the ROOTDataFrame
library and takes care of implication on the build system. The option is
enabled by default unless a 32bit system is detected.

[Exp PyROOT] Implemented the possibility to call a namespace inside cppyy.gbl.ROOT by typing simply ROOT.namespace instead of ROOT.ROOT.namespace

We should not expect users to know when is the best time to enable
autoloading in the interpreter.

We add __radd__, __rsub__, __rmul__ and __rtruediv__/__rdiv__

The warnings are triggered by the use of the Py_RETURN_TRUE and
Py_RETURN_FALSE macros of the Python C API. The use of such macros
is necessary and cannot be worked around.

The option is disabled on Windows since it does not exist.

The Python C API already provides these convenience macros.

The bug has been reported and fixed in upstream CPyCppyy.

The equality and inequality operators are better implemented in C++,
since we need to need to rely on Cppyy's rich comparison if the object
we are comparing ourselves with is not a Python proxy or if it contains
a null pointer. For example, we need to support the comparison to None.

The rest of comparison operators (i.e. those that define order)
can be implemented in Python, throwing a NotImplemented exception
if we are not comparing two proxies to TObject or derivate.

Its op-> is in a base class!

When drawing a TPad, it gets added to the list of primititves of its
mother TPad (fMother) with kCanDelete == 1. This means that, when
fMother is destructed, it will attempt to destroy its child TPad too.
To prevent a double delete, here we instruct the Python proxy of the
child C++ TPad being drawn not to destroy the latter (ROOT-10060).

A similar principle is applied to TButton, TColorWheel, TPolyLine3D,
TPolyMarker and TPolyMarker3D, whose kCanDelete bit is set in one of
their constructors. Later, when being drawn, they are appended to
the list of primitives of gPad.

TSlider is a special case, since it is appended to gPad already
in one of its constructors, after setting kCanDelete.
Therefore, we need to set the ownership when constructing the
object and not in Draw (TSlider does not need to be drawn).
This is ROOT-10095.

By default, PyROOT will send sys.argv to TApplication for the
arguments to be parsed. User arguments for the Python script
can be passed after a "-" or "--" in the command line and
they will be ignored by PyROOT.

The user can disable the aforementioned argument parsing by
adding a configuration option before any lookup in the ROOT module:
> import ROOT
> ROOT.PyConfig.IgnoreCommandLineOptions = True

This commit introduces the logic to display ROOT graphics when
using Python interactively. For that purpose, hooks are installed
to process the GUI events and to update the display.

Note that the threading approach is not used anymore: no thread
is explicitly created to process the events. The code based on
hooks should work on all the platforms, but it needs to be
tested. For the same reason, some code that handled the
threading case on Windows has been removed for now, and will be
restored only if necessary.

Most of the code has been picked from several parts of the
current ROOT.py and put together in the configuration of the
PyROOT TApplication.

The activation of the graphics is triggered only if ROOT is not
in batch mode. Such mode can be set by the user right after
importing ROOT.

The RPyROOTApplication is a TApplication that sets up the nuts
and bolts for interactive ROOT use from Python, closely
following TRint.

Variables are detected as used initialized if initialization is done via
a call to the interpreter.

The warning is introduced starting with gcc8 (cast-function-type).

Register keyword is deprecated since C++11. Observed with Python 2.7
installation and AppleClang/gcc7 in combination with C++17.

Set missing initializer in list, warning seen with gcc 7 and 8.