Find classes and values

Ontology classes are Python classes. Enumeration values, such as media and roles, are EnumValue objects in the package’s enums module. Both can be browsed as trees.

Browse a class branch

from plumb.watr import Process

print(Process.meta.tree(max_depth=2))

Process
├── Process_BiologicalProcess
│   ├── Process_ActivatedSludge
│   ├── Process_Biofiltration
│   ├── Process_Composting
│   ├── Process_Denitrification
│   ├── Process_Digestion
│   ├── Process_EnhancedBiologicalPhosphorusRemoval
│   └── Process_Nitrification
├── Process_ChemicalProcess
│   ├── Process_ChemicalPrecipitation
│   ├── Process_Combustion
│   ├── Process_Dosing
│   ├── Process_Electrodialysis
│   ├── Process_Electrolysis
│   ├── Process_Flocculation
│   ├── Process_HighDensitySludge
│   ├── Process_Hydrolysis
│   ├── Process_IonExchange
│   ├── Process_Oxidation
│   ├── Process_Reduction
│   └── Process_SolventExtraction
└── Process_PhysicalProcess
    ├── Process_Adsorption
    ├── Process_Cleaning
    ├── Process_Combustion
    ├── Process_Comminution
    ├── Process_Condensation
    ├── Process_Electrocoagulation
    ├── Process_Electrooxidation
    ├── Process_Evaporation
    ├── Process_GasTransfer
    ├── Process_HighDensitySludge
    ├── Process_IonExchange
    ├── Process_LandApplication
    ├── Process_Landfilling
    ├── Process_Mixing
    ├── Process_Recirculation
    ├── Process_Separation
    ├── Process_Solidification
    ├── Process_ThermalTreatment
    └── Process_UVIrradiation

Attribute	Gives
meta.children	direct subclasses
meta.descendants	all subclasses
meta.parents	direct parents
meta.tree(max_depth=...)	printable subtree

A class with several parents appears under each one.

Select a class

Look up a class within a branch by short name, Python name, or IRI:

from plumb.watr import Process_ReverseOsmosis

selected = Process.meta["ReverseOsmosis"]
selected is Process_ReverseOsmosis, selected.meta.iri

(True, 'https://watermetadata.org/ontology/watr#Process-ReverseOsmosis')

The lookup raises KeyError outside the branch. issubclass() and isinstance() work as usual.

Inspect a class

.meta gives a class’s ontology provenance:

from plumb.watr import SedimentationTank

SedimentationTank.meta.iri, SedimentationTank.meta.label, SedimentationTank.meta.parents

('https://watermetadata.org/ontology/watr#SedimentationTank',
 'Sedimentation Tank',
 (plumb.watr.SeparationTank,))

print(SedimentationTank.meta.definition)

A tank in which suspended solids separate from water by settling under gravity

meta.properties lists the generated attributes and describe_ports() the connection points. On an object, meta.instance_iri and meta.model identify it.

List every class

Each package’s REGISTRY lists its classes:

from plumb import watr

len(watr.REGISTRY.classes), watr.REGISTRY.resolve("Process_ReverseOsmosis")

(709, plumb.watr.Process_ReverseOsmosis)

The class catalog lists every S223 and WaTr class.

Browse enumeration values

enums.values holds every value under a flat name. The top level of enums holds the branches, for tab completion:

from plumb.watr import enums

water = enums.Substance.Medium.Mix.Fluid.Water
water is enums.values.Fluid_Water

True

water.tree(max_depth=2)

Fluid-Water
├── Water-Brackish
├── Water-Brine
├── Water-ChilledWater
├── Water-Freshwater
├── Water-GlycolSolution
│   ├── GlycolSolution-15Percent
│   └── GlycolSolution-30Percent
├── Water-HotWater
├── Water-Seawater
└── Water-Steam

Values have children, descendants, parent, and parents, without a .meta step. tree_text() returns the tree as a string.

Select a value

Bracket lookup searches a subtree by short name, flat name, or IRI:

chilled = enums.values.Water_ChilledWater
water["ChilledWater"] is chilled, water[chilled.iri] is chilled

(True, True)

An ambiguous short name raises KeyError listing the matches.

Check ancestry

is_a() follows every parent:

sludge = enums.values.Fluid_Sludge
sludge.is_a(enums.values.Mix_Fluid), sludge.is_a(enums.values.Fluid_Water)

(True, False)

Sludge is a fluid mixture, not a kind of water.