unyt.unit_registry module¶

A registry for units that can be added to and modified.

unyt.unit_registry.cached_sympify[source]

Successive loads of unit systems produce the same calls to sympify in UnitRegistry.from_json. Even within a single load, this is a net improvement because there will often be a few cache hits

class unyt.unit_registry.UnitRegistry(add_default_symbols=True, lut=None, unit_system=None)[source]

Bases: object

A registry for unit symbols

unit_system_id

This is a unique identifier for the unit registry created from a FNV hash. It is needed to register a dataset’s code unit system in the unit system registry.

prefixable_units
add(symbol, base_value, dimensions, tex_repr=None, offset=None, prefixable=False)[source]

Add a symbol to this registry.

Parameters: symbol (str) – The name of the unit base_value (float) – The scaling from the units value to the equivalent SI unit with the same dimensions dimensions (expr) – The dimensions of the unit tex_repr (str, optional) – The LaTeX representation of the unit. If not provided a LaTeX representation is automatically generated from the name of the unit. offset (float, optional) – If set, the zero-point offset to apply to the unit to convert to SI. This is mostly used for units like Farhenheit and Celcius that are not defined on an absolute scale. prefixable (bool) – If True, then SI-prefix versions of the unit will be created along with the unit itself.
remove(symbol)[source]

Remove the entry for the unit matching symbol.

Parameters: symbol (str) – The name of the unit symbol to remove from the registry.
modify(symbol, base_value)[source]

Change the base value of a unit symbol. Useful for adjusting code units after parsing parameters.

Parameters: symbol (str) – The name of the symbol to modify base_value (float) – The new base_value for the symbol.
keys()[source]

Print out the units contained in the lookup table.

to_json()[source]

Returns a json-serialized version of the unit registry

classmethod from_json(json_text)[source]

Returns a UnitRegistry object from a json-serialized unit registry

Parameters: json_text (str) – A string containing a json represention of a UnitRegistry
list_same_dimensions(unit_object)[source]

Return a list of base unit names that this registry knows about that are of equivalent dimensions to unit_object.

unyt.unit_registry.default_unit_registry = <unyt.unit_registry.UnitRegistry object>

The default unit registry