Replaced 'importlib.util.find_spec' with 'pkgutil.find_loader' to ensure...

Replaced 'importlib.util.find_spec' with 'pkgutil.find_loader' to ensure Python 2.7 compatibility. Updated minimal version of geoarray.

arosics/__init__.py

@@ -2,8 +2,8 @@
 
 """Top-level package for arosics."""
 
-import warnings
-from importlib import util
+import warnings as _warnings
+from pkgutil import find_loader as _find_loader
 
 from arosics.CoReg import COREG
 from arosics.CoReg_local import COREG_LOCAL
@@ -22,7 +22,5 @@ __all__ = ['COREG',
 
 
 # check optional dependencies
-if not util.find_spec('pyfftw'):
-    warnings.warn('PYFFTW library is missing. However, coregistration works. But in some cases it can be much slower.')
-
-del util, warnings
+if not _find_loader('pyfftw'):
+    _warnings.warn('PYFFTW library is missing. However, coregistration works. But in some cases it can be much slower.')

requirements.txt

-geoarray>=0.8.0
+geoarray>=0.8.8
 py_tools_ds>=0.13.7
 cmocean
 numpy

setup.py

@@ -5,7 +5,8 @@
 
 from setuptools import setup, find_packages
 import warnings
-from importlib import util
+from pkgutil import find_loader
+
 
 with open('README.rst') as readme_file:
     readme = readme_file.read()
@@ -17,7 +18,7 @@ version = {}
 with open("arosics/version.py") as version_file:
     exec(version_file.read(), version)
 
-requirements = ['numpy', 'gdal', 'shapely', 'scikit-image', 'matplotlib', 'geopandas', 'geoarray>=0.8.0',
+requirements = ['numpy', 'gdal', 'shapely', 'scikit-image', 'matplotlib', 'geopandas', 'geoarray>=0.8.8',
                 'py_tools_ds>=0.13.7', 'plotly', 'cmocean', 'six', 'folium>=0.6.0', 'geojson'
                 # 'pykrige'  # conda install --yes -c conda-forge pykrige
                 # 'pyfftw', # conda install --yes -c conda-forge pyfftw=0.10.4 ; \
@@ -66,16 +67,16 @@ setup(
 
 
 # check for pyfftw
-if not util.find_spec('pyfftw'):
+if not find_loader('pyfftw'):
     warnings.warn('You need to install pyfftw manually (see https://pypi.python.org/pypi/pyFFTW) for speeding up '
                   'the computation. It is not automatically installed.')
 
 # check for basemap
-if not util.find_spec('mpl_toolkits.basemap'):
+if not find_loader('mpl_toolkits.basemap'):
     warnings.warn('You need to install basemap manually if you want to plot maps (see www./matplotlib.org/basemap). '
                   'It is not automatically installed.')
 
 # check for pykrige
-if not util.find_spec('pykrige'):
+if not find_loader('pykrige'):
     warnings.warn('You need to install pykrige manually if you want to interpolate tie point grids produced by AROSICS '
                   '(see https://github.com/bsmurphy/PyKrige). It is not automatically installed.')

tests/CI_docker/context/environment_arosics.yml

@@ -46,5 +46,5 @@ dependencies:
     - rednose
     - cmocean
     - plotly
-    - geoarray>=0.8.0
+    - geoarray>=0.8.8
     - py_tools_ds>=0.13.7

tests/test_COREG_LOCAL.py

@@ -6,7 +6,7 @@
 import unittest
 import shutil
 import os
-from importlib import util
+from pkgutil import find_loader
 
 # custom
 from .cases import test_cases
@@ -64,12 +64,12 @@ class CompleteWorkflow_INTER1_S2A_S2A(unittest.TestCase):
         CRL.CoRegPoints_table
 
         # test tie point grid visualization
-        if util.find_spec('mpl_toolkits.basemap'):  # only works if basemap is installed
+        if find_loader('mpl_toolkits.basemap'):  # only works if basemap is installed
             CRL.view_CoRegPoints(hide_filtered=True)
             CRL.view_CoRegPoints(hide_filtered=False)
             CRL.view_CoRegPoints(shapes2plot='vectors')
 
-        if util.find_spec('folium') and util.find_spec('geojson'):
+        if find_loader('folium') and find_loader('geojson'):
             CRL.view_CoRegPoints_folium()
 
         # test shift correction and output writer

tests/test_tie_point_grid.py

@@ -6,7 +6,7 @@
 import unittest
 import tempfile
 import os
-from importlib import util
+from pkgutil import find_loader
 import shutil
 
 # custom
@@ -88,7 +88,7 @@ class Test_Tie_Point_Grid(unittest.TestCase):
             self.assertTrue(os.path.isfile(outpath))
 
     def test_to_Raster_using_Kriging(self):
-        if util.find_spec('pykrige.ok'):
+        if find_loader('pykrige.ok'):
             with tempfile.TemporaryDirectory() as tmpdir:
                 outpath = os.path.join(tmpdir, 'X_SHIFT_M__interpolated.bsq')
                 self.TPG.to_Raster_using_Kriging(attrName='X_SHIFT_M', fName_out=outpath)