Some clean up

paicos/__init__.py

@@ -35,7 +35,7 @@
 
 # HDF5 file writers
 from .writers.paicos_writer import PaicosWriter, PaicosTimeSeriesWriter
-from .writers.arepo_image import ArepoImage
+from .writers.arepo_image import ImageWriter, ArepoImage
 
 # Image creators
 from .image_creators.image_creator import ImageCreator
@@ -250,28 +250,31 @@ def import_user_settings():
 
     :meta private:
     """
+    data_dir = None
+    if os.path.exists(root_dir + 'data/'):
+        data_dir = root_dir + 'data/'
     if os.path.exists(code_dir + '/paicos_user_settings.py'):
         from . import paicos_user_settings
+        if hasattr(paicos_user_settings, 'data_dir'):
+            data_dir = paicos_user_settings.data_dir
     if os.path.exists(home_dir + '/.paicos_user_settings.py'):
         filepath = home_dir + '/.paicos_user_settings.py'
         import importlib
         spec = importlib.util.spec_from_file_location('paicos_settings',
                                                       location=filepath)
         foo = importlib.util.module_from_spec(spec)
         spec.loader.exec_module(foo)
+        if hasattr(foo, 'data_dir'):
+            data_dir = foo.data_dir
 
-
-import_user_settings()
-
-if os.path.exists(root_dir + 'data/'):
-    data_dir = root_dir + 'data/'
-else:
-    try:
-        from .paicos_user_settings import data_dir
+    if data_dir is not None:
         if data_dir[-1] != '/':
             data_dir += '/'
-    except:  # noqa: E722
-        data_dir = None
+
+    return data_dir
+
+
+data_dir = import_user_settings()
 
 
 # Import of GPU functionality only if
@@ -296,7 +299,8 @@ def gpu_init(gpu_num=0):
         import cupy as cp
         from numba import cuda
 
-        cp.cuda.Device(gpu_num).use()
+        if gpu_num != 0:
+            cp.cuda.Device(gpu_num).use()
 
         @cuda.jit
         def my_kernel(io_array):

paicos/readers/paicos_readers.py

@@ -527,9 +527,13 @@ def find_unit(self, name, field):
 
         if unit is False:
             msg = ('\n\nUnit for field:{}, blockname:{} not implemented!'
-                   + '\nPlease add it to unit_specifications '
+                   + '\nYou can get rid of this error by changing your '
+                   + 'settings, i.e.,\n\npa.settings.strict_units = False\n\n'
+                   + 'However, this means that this quantity will not be read in. '
+                   + 'If you need this quantity, then the best way forward is to '
+                   + 'add it to the unit_specifications '
                    + 'by using the pa.add_user_units '
-                   + 'function. You can also add the pa.add_user_units call to your'
+                   + 'function. You can also add the pa.add_user_units call to your '
                    + 'Paicos user settings to avoid having to do this more than once. '
                    + 'Alternatively, please create an issue on GitHub if you think '
                    + 'others could benefit from that.'

paicos/writers/arepo_image.py

@@ -122,3 +122,6 @@ def _perform_extra_consistency_checks(self):
                 np.testing.assert_array_equal(widths, self.widths)
 
             assert f['image_info'].attrs['direction'] == self.direction
+
+
+ImageWriter = ArepoImage