YTEP-0019: Reduce items in main import


Created: October 2, 2013 Author: Matthew Turk

Currently, yt.mods includes a huge number of items, polluting the namespace considerably. Many of these are not necessary, as they are seldom used.



Detailed Description

Currently, the number of items in the yt.mods namespace is enourmous. There are 276 items (including module builtins.) By providing a better set of namespaces, we can make all of these items accessible without polluting the namespace itself.

As an example, we should expose the load command primarily, and encourage directly importing frontend-specific code if that code needs to be interacted with.

This YTEP concerns two changes in functionality.

  • Reduce the number of items in yt.mods.
  • Make yt.mods a superset of functionality of yt/ This means (which includes argument parsing, parallel initialization, configuration system reading, and so on.)

This will change some aspects of behavior, as it will make operations that currently require the ytcfg variable to be modified before any other startup_tasks code is executed no longer possible. This number is extremely small, and the primary one is loglevel setting, which is easily exposed in mylog.setLevel.

Primarily, we want to make yt exist better as a module as well as an environment.

Current Imports

These are the items currently imported, and their proposed status.

We can implement this either through not importing into the main namespace items we do not want to include, or by explicitly enumerating the items to include in an __all__ attribute.

A few comments on specific items:

  • TransferFunction classes have been removed and we should investigate other ways of exposing them. One option would be importing the module transfer_functions and accessing attributes.
  • HaloFinder has been removed, so a new method for setting up this process easily and transparently (perhaps with amods) is needed.
  • add_grad should probably have a new name.
Object Include
ARTFieldInfo No
ARTIOFieldInfo No
ARTIOStaticOutput No
ARTStaticOutput No
AnalysisTask No
ArrowCallback No
AthenaFieldInfo No
AthenaStaticOutput No
BinnedProfile1D Yes
BinnedProfile2D Yes
BinnedProfile3D Yes
Camera No
CastroFieldInfo No
CastroStaticOutput No
ChomboFieldInfo No
ChomboStaticOutput No
ClumpContourCallback No
ColorTransferFunction No
ContourCallback No
CoordAxesCallback No
CuttingQuiverCallback No
DummyProgressBar No
EnzoFieldInfo No
EnzoSimulation No
EnzoStaticOutput No
EnzoStaticOutputInMemory No
EnzoTestOutputFileNonExistent No
FLASHFieldInfo No
FLASHStaticOutput No
FieldInfo No
FixedResolutionBuffer Yes
FlashRayDataCallback No
GDFFieldInfo No
GDFStaticOutput No
GUIProgressBar No
GadgetFieldInfo No
GadgetHDF5StaticOutput No
GadgetStaticOutput No
GridBoundaryCallback No
HaloFinder No
HomogenizedVolume No
HopCircleCallback No
HopParticleCallback No
ImageArray Yes
ImageLineCallback No
InvalidSimulationTimeSeries No
LabelCallback No
LinePlotCallback No
LooseVersion No
MagFieldCallback No
MarkerAnnotateCallback No
MaterialBoundaryCallback No
MissingParameter No
MoabFieldInfo No
MoabHex8StaticOutput No
MosaicFisheyeCamera No
NoCUDAException No
NoStoppingCondition No
NyxFieldInfo No
NyxStaticOutput No
OWLSFieldInfo No
OWLSStaticOutput No
ObliqueFixedResolutionBuffer Yes
OffAxisProjectionPlot Yes
OffAxisSlicePlot Yes
OrionFieldInfo No
OrionStaticOutput No
ParallelProgressBar No
ParticleCallback No
ParticleTrajectoryCollection Yes
PlanckTransferFunction No
PlotCallback No
PlotCollection Yes
PlotCollectionInteractive Yes
PlutoFieldInfo No
PlutoStaticOutput No
PointAnnotateCallback No
ProjectionPlot Yes
ProjectionTransferFunction No
PyneMoabHex8StaticOutput No
QuiverCallback No
RAMSESFieldInfo No
RAMSESStaticOutput No
SlicePlot Yes
SphereCallback No
StreamFieldInfo No
StreamHandler No
StreamStaticOutput No
StreamlineCallback No
TextLabelCallback No
TigerFieldInfo No
TigerStaticOutput No
TimeSeriesData Yes
TimestampCallback No
TipsyFieldInfo No
TipsyStaticOutput No
TitleCallback No
UnitBoundaryCallback No
ValidateDataField Yes
ValidateGridType Yes
ValidateParameter Yes
ValidateProperty Yes
ValidateSpatial Yes
VelocityCallback Yes
YTAxesNotOrthogonalError No
YTCannotParseFieldDisplayName No
YTCannotParseUnitDisplayName No
YTCloudError No
YTCoordinateNotImplemented No
YTCouldNotGenerateField No
YTDataSelectorNotImplemented No
YTDomainOverflow No
YTEllipsoidOrdering No
YTEmptyClass No
YTException No
YTFieldNotFound No
YTFieldNotParseable No
YTFieldTypeNotFound No
YTGeometryNotSupported No
YTHubRegisterError No
YTIllDefinedBounds No
YTIllDefinedFilter No
YTInvalidWidthError No
YTNoDataInObjectError No
YTNoFilenamesMatchPattern No
YTNoOldAnswer No
YTNotDeclaredInsideNotebook No
YTNotInsideNotebook No
YTObjectNotImplemented No
YTOutputNotIdentified No
YTParticleDepositionNotImplemented No
YTRockstarMultiMassNotSupported No
YTSimulationNotIdentified No
YTSphereTooSmall No
YTTooManyVertices No
YTUnitNotRecognized No
__builtins__ No
__doc__ No
__file__ No
__level No
__name__ No
__package__ No
__startup_tasks No
_fn No
absolute_import No
add_art_field No
add_artio_field No
add_athena_field No
add_castro_field No
add_chombo_field No
add_enzo_1d_field No
add_enzo_2d_field No
add_enzo_field No
add_field Yes
add_flash_field No
add_gadget_field No
add_gdf_field No
add_grad Yes
add_moab_field No
add_nyx_field No
add_orion_field No
add_owls_field No
add_pluto_field No
add_quantity No
add_ramses_field No
add_stream_field No
add_tiger_field No
add_tipsy_field No
amods Yes
analysis_task No
annotate_image Yes
apply_colormap Yes
available_analysis_modules Yes
axis_names No
bb_apicall No
cPickle No
callback_registry No
ceil No
cls No
contextlib No
data_object_registry No
defaultdict No
deprecate No
derived_field Yes
ensure_dir_exists No
ensure_list No
ensure_numpy_array No
ensure_tuple No
fix_axis No
fix_length No
floor No
get_available_modules No
get_hg_version No
get_image_suffix No
get_ipython_api_version No
get_memory_usage Yes
get_multi_plot Yes
get_num_threads No
get_pbar Yes
get_script_contents No
get_version_stack Yes
get_yt_supp Yes
get_yt_version Yes
glob No
humanize_time No
imgur_upload No
insert_ipython Yes
inspect No
inv_axis_names No
is_root Yes
iterable Yes
just_one No
load Yes
load_amr_grids Yes
load_hexahedral_mesh Yes
load_particles Yes
load_uniform_grid Yes
my_plugin_name No
mylog Yes
na No
name No
np Yes
numpy No
off_axis_projection Yes
only_on_root Yes
ortho_find Yes
os No
parallel_objects Yes
parallel_profile Yes
particle_filter Yes
paste_traceback No
paste_traceback_detailed No
pb No
pdb No
pdb_run No
periodic_position Yes
physical_constants Yes
print_tb Yes
projload No
quantity_info No
quartiles Yes
read_struct No
resource No
rootloginfo No
rootonly Yes
rpdb No
scale_image Yes
show_colormaps Yes
signal No
signal_ipython No
signal_print_traceback No
signal_problem No
simulation Yes
struct No
subprocess No
sys No
time No
time_execution No
time_function No
traceback No
traceback_writer_hook No
types No
unparsed_args Yes
update_hg No
warnings No
wraps No
write_bitmap Yes
write_fits Yes
write_image Yes
write_projection Yes
x_dict No
y_dict No
yt_counters No
ytcfg Yes
ytcfgDefaults No

Changing yt/ to Import

The second aspect of this YTEP is to change the yt module to include everything that is in yt.mods, but without the side effects that come from yt.startup_tasks. Because importing submodules necessarily will then import, this means submodules cannot be imported without the whole of yt that is exposed in being imported.

This primarily will affect configuration options, which are largely no longer necessary to modify directly at runtime. Additionally, the old behavior can still be preserved by yt.mods.

Backwards Compatibility

This may break compatibility, although nearly all of the items removed are items that are not typically used in scripts. This list can be modified.

Note that importing frontends into a namespace will still enable them to be used in load.

Importing yt.mods will still act as before, with option parsing and the like. Importing yt.config will result in the config file being parsed once; this means runtime options will need to be modified differently.


We could identify additional means of reducing the namespace pollution, but this is the main one that I see.

We could also not put anything into yt/