On Fri, Mar 1, 2019 at 11:24 AM <balducci@units.it> wrote:

python-3.8.0 (alpha) emits the following warning on numpy/ma/core.py (verified up to official 1.16.2):

----8<---- /usr/python3/site_python3/lib64/numpy.egg/numpy/ma/core.py:4466: SyntaxWarning: "is" with a literal. Did you mean "=="? if self.shape is (): /usr/python3/site_python3/lib64/numpy.egg/numpy/ma/core.py:4466: SyntaxWarning: "is" with a literal. Did you mean "=="? if self.shape is (): /usr/python3/site_python3/lib64/numpy.egg/numpy/core/include ---->8---- Hi,

I believe the warning is really helpful, testing for an empty tuple with `is` probably only works because of a CPython implementation detail (namely that the empty tuple is interned by the interpreter). In other words, this seems like a bug which is fixed by using == instead. Regards, András

In turn, this breaks boost's numpy detection, which is done with:

----8<---- notice: [python-cfg] running command '/usr/python3/bin/python -c "import sys; sys.stderr = sys.stdout; import numpy; print(numpy.get_include())"' ---->8----

and thus produces an unusable include path (containing the warning message from python)

The following:

----8<---- *** numpy/ma/core.py.PYTHON_3_8_COMPAT Wed Feb 27 12:45:06 2019 --- numpy/ma/core.py Wed Feb 27 12:45:06 2019 *************** *** 4463,4469 **** if m is nomask: # compare to _count_reduce_items in _methods.py

! if self.shape is (): if axis not in (None, 0): raise np.AxisError(axis=axis, ndim=self.ndim) return 1 --- 4463,4469 ---- if m is nomask: # compare to _count_reduce_items in _methods.py

! if self.shape == (): if axis not in (None, 0): raise np.AxisError(axis=axis, ndim=self.ndim) return 1 ---->8----

fixes everything for me

thanks ciao -g

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