move pdal python support into a new package

[martinl]

Currently pdal package has a lot of dependencies including Python3 and related packages, see ​https://trac.osgeo.org/grass/ticket/2732#comment:29. Python3 dependencies will enlarge significantly GRASS Windows standalone binaries since GRASS uses Python2 only.

Would be useful to split current package into pdal and python3-pdal to avoid Python3 dependency for core pdal package (similarly to other packages like gdal, python3-gdal, etc.)

[martinl]

I wonder why setup.hint (1) contains dependencies like python3-numpy, python3-gdal, and python3-matplotlib. In the package I found only bin, include and lib directories, nothing seems to be Python related here. Thanks for clarification in advance.

(1) ​http://download.osgeo.org/osgeo4w/x86_64/release/pdal/setup.hint (2) ​http://download.osgeo.org/osgeo4w/x86_64/release/pdal/pdal-1.7.2-1.tar.bz2

[jef]

Same applies to GRASS - it also introduces a python2 dependency to QGIS3…

[martinl]

Right. But, well, it's not answer for the question why there is for pdal Python3 dependencies.

[hobu]

the question why there is for pdal Python3 dependencies

PDAL both embeds and extends Python, and it is built against Python3 for OSGeo4W, not Python2. The pdal-python package will not work against Python2. There is some background on the topic at ​https://github.com/PDAL/PDAL/issues/1478

PDAL depends upon Numpy when it extends Python.

The matplotlib dependency is a convenience for the PDAL workshop example ​https://pdal.io/workshop/exercises/python/histogram.html