ENH: never import ytcfg at the top level of a module, so that yt.conf…

…ig doesn't need to be run at all at import time

yt/data_objects/construction_data_containers.py

@@ -11,7 +11,6 @@
 from more_itertools import always_iterable
 from tqdm import tqdm
 
-from yt.config import ytcfg
 from yt.data_objects.field_data import YTFieldData
 from yt.data_objects.selection_objects.data_selection_objects import (
     YTSelectionContainer1D,
@@ -497,6 +496,8 @@ def _mrep(self):
         return MinimalProjectionData(self)
 
     def deserialize(self, fields):
+        from yt.config import ytcfg
+
         if not ytcfg.get("yt", "serialize"):
             return False
         for field in fields:
@@ -516,6 +517,8 @@ def deserialize(self, fields):
         return deserialized_successfully
 
     def serialize(self):
+        from yt.config import ytcfg
+
         if not ytcfg.get("yt", "serialize"):
             return
         self._mrep.store(self.ds.parameter_filename + ".yt")
@@ -1882,6 +1885,8 @@ def export_obj(
         ...     )
 
         """
+        from yt.config import ytcfg
+
         if color_map is None:
             color_map = ytcfg.get("yt", "default_colormap")
         if self.vertices is None:
@@ -2001,6 +2006,8 @@ def _export_obj(
         emit_field_max=None,
         emit_field_min=None,
     ):
+        from yt.config import ytcfg
+
         if color_map is None:
             color_map = ytcfg.get("yt", "default_colormap")
         if plot_index is None:
@@ -2213,6 +2220,8 @@ def export_blender(
         ...     )
 
         """
+        from yt.config import ytcfg
+
         if color_map is None:
             color_map = ytcfg.get("yt", "default_colormap")
         if self.vertices is None:
@@ -2258,6 +2267,8 @@ def _export_blender(
         emit_field_max=None,
         emit_field_min=None,
     ):
+        from yt.config import ytcfg
+
         if color_map is None:
             color_map = ytcfg.get("yt", "default_colormap")
         if plot_index is None:
@@ -2359,6 +2370,8 @@ def export_ply(
         ... ]
         >>> surf.export_ply("my_galaxy.ply", bounds=bounds)
         """
+        from yt.config import ytcfg
+
         if color_map is None:
             color_map = ytcfg.get("yt", "default_colormap")
         if self.vertices is None:
@@ -2394,6 +2407,8 @@ def _export_ply(
         color_log=True,
         sample_type="face",
     ):
+        from yt.config import ytcfg
+
         if color_map is None:
             color_map = ytcfg.get("yt", "default_colormap")
         if hasattr(filename, "read"):
@@ -2548,6 +2563,8 @@ def export_sketchfab(
         ... )
         ...
         """
+        from yt.config import ytcfg
+
         if color_map is None:
             color_map = ytcfg.get("yt", "default_colormap")
         api_key = api_key or ytcfg.get("yt", "sketchfab_api_key")

yt/data_objects/image_array.py

@@ -2,7 +2,6 @@
 
 import numpy as np
 
-from yt.config import ytcfg
 from yt.units.yt_array import YTArray
 from yt.visualization.image_writer import write_bitmap, write_image
 
@@ -387,6 +386,8 @@ def write_image(
         >>> im_arr.write_image("test_ImageArray.png")
 
         """
+        from yt.config import ytcfg
+
         if cmap_name is None:
             cmap_name = ytcfg.get("yt", "default_colormap")
         if filename is not None and filename[-4:] != ".png":

yt/data_objects/index_subobjects/grid_patch.py

@@ -5,7 +5,6 @@
 import numpy as np
 
 import yt.geometry.particle_deposit as particle_deposit
-from yt.config import ytcfg
 from yt.data_objects.selection_objects.data_selection_objects import (
     YTSelectionContainer,
 )
@@ -20,8 +19,6 @@
 from yt.utilities.lib.mesh_utilities import clamp_edges
 from yt.utilities.nodal_data_utils import get_nodal_slices
 
-RECONSTRUCT_INDEX = bool(ytcfg.get("yt", "reconstruct_index"))
-
 
 class AMRGridPatch(YTSelectionContainer):
     _spatial = True
@@ -163,14 +160,16 @@ def _prepare_grid(self):
         # This is definitely the slowest part of generating the index
         # Now we give it pointers to all of its attributes
         # Note that to keep in line with Enzo, we have broken PEP-8
+        from yt.config import ytcfg
+
         h = self.index  # cache it
         my_ind = self.id - self._id_offset
         self.ActiveDimensions = h.grid_dimensions[my_ind]
         self.LeftEdge = h.grid_left_edge[my_ind]
         self.RightEdge = h.grid_right_edge[my_ind]
         # This can be expensive so we allow people to disable this behavior
         # via a config option
-        if RECONSTRUCT_INDEX:
+        if ytcfg.get("yt", "reconstruct_index"):
             if is_sequence(self.Parent) and len(self.Parent) > 0:
                 p = self.Parent[0]
             else:

yt/data_objects/particle_trajectories.py

@@ -1,6 +1,5 @@
 import numpy as np
 
-from yt.config import ytcfg
 from yt.data_objects.field_data import YTFieldData
 from yt.funcs import get_pbar, mylog
 from yt.units.yt_array import array_like_field
@@ -59,6 +58,7 @@ class ParticleTrajectories:
     def __init__(
         self, outputs, indices, fields=None, suppress_logging=False, ptype=None
     ):
+        from yt.config import ytcfg
 
         indices.sort()  # Just in case the caller wasn't careful
         self.field_data = YTFieldData()
@@ -218,6 +218,7 @@ def _get_data(self, fields):
         The trajectory collection itself is a dict of 2D numpy arrays,
         with shape (num_indices, num_steps)
         """
+        from yt.config import ytcfg
 
         missing_fields = [field for field in fields if field not in self.field_data]
         if not missing_fields:

yt/data_objects/static_output.py

@@ -14,7 +14,6 @@
 from unyt.exceptions import UnitConversionError, UnitParseError
 
 from yt._maintenance.deprecation import issue_deprecation_warning
-from yt.config import ytcfg
 from yt.data_objects.particle_filters import filter_registry
 from yt.data_objects.particle_unions import ParticleUnion
 from yt.data_objects.region_expression import RegionExpression
@@ -57,7 +56,9 @@
 
 
 _cached_datasets = weakref.WeakValueDictionary()
-_ds_store = ParameterFileStore()
+
+# TODO: this needs an actual solution
+_ds_store = None  # ParameterFileStore()
 
 
 def _unsupported_object(ds, obj_name):
@@ -149,6 +150,8 @@ class Dataset(abc.ABC):
     domain_center = MutableAttribute(True)
 
     def __new__(cls, filename=None, *args, **kwargs):
+        from yt.config import ytcfg
+
         if not isinstance(filename, str):
             obj = object.__new__(cls)
             # The Stream frontend uses a StreamHandler object to pass metadata

yt/data_objects/time_series.py

@@ -8,7 +8,6 @@
 import numpy as np
 from more_itertools import always_iterable
 
-from yt.config import ytcfg
 from yt.data_objects.analyzer_objects import AnalysisTask, create_quantity_proxy
 from yt.data_objects.particle_trajectories import ParticleTrajectories
 from yt.funcs import is_sequence, mylog
@@ -193,6 +192,8 @@ def _get_filenames_from_glob_pattern(outputs):
         Helper function to DatasetSeries.__new__
         handle a special case where "outputs" is assumed to be really a pattern string
         """
+        from yt.config import ytcfg
+
         pattern = outputs
         epattern = os.path.expanduser(pattern)
         data_dir = ytcfg.get("yt", "test_data_dir")

yt/fields/xray_emission_fields.py

@@ -2,7 +2,6 @@
 
 import numpy as np
 
-from yt.config import ytcfg
 from yt.fields.derived_field import DerivedField
 from yt.funcs import mylog, only_on_root, parse_h5_attr
 from yt.units.yt_array import YTArray, YTQuantity
@@ -20,6 +19,8 @@
 
 
 def _get_data_file(table_type, data_dir=None):
+    from yt.config import ytcfg
+
     data_file = "%s_emissivity_v%d.h5" % (table_type, data_version[table_type])
     if data_dir is None:
         supp_data_dir = ytcfg.get("yt", "supp_data_dir")

yt/frontends/amrvac/data_structures.py

@@ -15,7 +15,6 @@
 import numpy as np
 from more_itertools import always_iterable
 
-from yt.config import ytcfg
 from yt.data_objects.index_subobjects.grid_patch import AMRGridPatch
 from yt.data_objects.static_output import Dataset
 from yt.funcs import mylog, setdefaultattr
@@ -191,6 +190,7 @@ def __init__(
 
         """
         # note: geometry_override and parfiles are specific to this frontend
+        from yt.config import ytcfg
 
         self._geometry_override = geometry_override
         super().__init__(

yt/frontends/fits/data_structures.py

@@ -9,7 +9,6 @@
 import numpy.core.defchararray as np_char
 from more_itertools import always_iterable
 
-from yt.config import ytcfg
 from yt.data_objects.index_subobjects.grid_patch import AMRGridPatch
 from yt.data_objects.static_output import Dataset
 from yt.funcs import mylog, setdefaultattr
@@ -330,6 +329,7 @@ def __init__(
         units_override=None,
         unit_system="cgs",
     ):
+        from yt.config import ytcfg
 
         if parameters is None:
             parameters = {}

yt/frontends/owls/fields.py

@@ -2,7 +2,6 @@
 
 import numpy as np
 
-from yt.config import ytcfg
 from yt.fields.species_fields import (
     add_species_field_by_density,
     add_species_field_by_fraction,
@@ -319,6 +318,7 @@ def setup_fluid_fields(self):
     # exist it will download the data from http://yt-project.org/data
     # -------------------------------------------------------------
     def _get_owls_ion_data_dir(self):
+        from yt.config import ytcfg
 
         txt = "Attempting to download ~ 30 Mb of owls ion data from %s to %s."
         data_file = "owls_ion_data.tar.gz"

yt/frontends/ramses/definitions.py

@@ -1,8 +1,7 @@
 # These functions are RAMSES-specific
 import re
 
-from yt.config import ytcfg
-from yt.funcs import mylog
+# from yt.funcs import mylog
 
 
 def ramses_header(hvals):
@@ -69,6 +68,8 @@ def ramses_header(hvals):
     "gas_tracer": 0,
 }
 
+# TODO: this needs an actual solution
+"""
 if ytcfg.has_section("ramses-families"):
     for key in particle_families.keys():
         val = ytcfg.get("ramses-families", key, fallback=None)
@@ -77,3 +78,4 @@ def ramses_header(hvals):
                 "Changing family %s from %s to %s", key, particle_families[key], val
             )
             particle_families[key] = val
+"""

yt/frontends/ramses/field_handlers.py

@@ -3,7 +3,6 @@
 import os
 from typing import List
 
-from yt.config import ytcfg
 from yt.funcs import mylog
 from yt.utilities.cython_fortran_utils import FortranFile
 
@@ -305,6 +304,8 @@ class HydroFieldFileHandler(FieldFileHandler):
     @classmethod
     def detect_fields(cls, ds):
         # Try to get the detected fields
+        from yt.config import ytcfg
+
         detected_fields = cls.get_detected_fields(ds)
         if detected_fields:
             return detected_fields

yt/frontends/ramses/particle_handlers.py

@@ -1,7 +1,6 @@
 import abc
 import os
 
-from yt.config import ytcfg
 from yt.funcs import mylog
 from yt.utilities.cython_fortran_utils import FortranFile
 
@@ -60,6 +59,8 @@ def __init_subclass__(cls, *args, **kwargs):
         return cls
 
     def __init__(self, domain):
+        from yt.config import ytcfg
+
         self.setup_handler(domain)
 
         # Attempt to read the list of fields from the config file

yt/geometry/geometry_handler.py

@@ -4,7 +4,6 @@
 
 import numpy as np
 
-from yt.config import ytcfg
 from yt.units.yt_array import YTArray, uconcatenate
 from yt.utilities.exceptions import YTFieldNotFound
 from yt.utilities.io_handler import io_registry
@@ -54,6 +53,8 @@ def _initialize_state_variables(self):
         self.num_grids = None
 
     def _initialize_data_storage(self):
+        from yt.config import ytcfg
+
         if not ytcfg.get("yt", "serialize"):
             return
         fn = self.ds.storage_filename

yt/geometry/grid_geometry_handler.py

@@ -5,7 +5,6 @@
 import numpy as np
 
 from yt.arraytypes import blankRecordArray
-from yt.config import ytcfg
 from yt.fields.derived_field import ValidateSpatial
 from yt.fields.field_detector import FieldDetector
 from yt.funcs import ensure_numpy_array, iter_fields
@@ -402,6 +401,8 @@ def _chunk_io(
         preload_fields=None,
         chunk_sizing="auto",
     ):
+        from yt.config import ytcfg
+
         # local_only is only useful for inline datasets and requires
         # implementation by subclasses.
         if preload_fields is None: