Module Contents

class ifcopenshell.api.pset.edit_qto.Usecase
get_canonical_property_type(name, value)
get_primary_measure_type(name, previous_value=None)
ifcopenshell.api.pset.edit_qto.edit_qto(file, qto=None, name=None, properties=None, pset_template=None) None

Edits a quantity set and its quantities

At its simplest usage, this may be used to edit the name of a quantity set. It may also be used to add, edit, or remove quantities.

See ifcopenshell.api.pset.edit_pset for documentation on how this is intended to be used.

One major difference is that quantities set to None are always purged. It is not allowed to have None quantities in IFC.

  • qto (ifcopenshell.entity_instance) – The IfcElementQuantity to edit.

  • name (str, optional) – A new name for the quantity set. If no name is specified, the quantity set name is not changed.

  • properties (dict) – A dictionary of properties. The keys must be a string of the name of the quantity. The data type of the value will be determined by the quantity set template. If no quantity set template is found, the data types of the Python values will influence the IFC data type of the quantity. String values will become IfcLabel, float values will become IfcReal, booleans will become IfcBoolean, and integers will become IfcInteger. If more control is desired, you may explicitly specify IFC data objects directly.

  • pset_template (ifcopenshell.entity_instance) – If a quantity set template is provided, this will be used to determine data types. If no user-defined template is provided, the built-in buildingSMART templates will be loaded.



Return type:



# Let's imagine we have a new wall type.
wall = ifcopenshell.api.run("root.create_entity", model, ifc_class="IfcWall")

# This is a standard buildingSMART property set.
qto = ifcopenshell.api.run("pset.add_qto", model, product=wall, name="Qto_WallBaseQuantities")

# In this scenario, we don't specify any pset_template because it is
# part of the built-in buildingSMART templates, and so the Length
# will automatically be an IfcLengthMeasure, and the NetVolume will
# automatically be an IfcVolumeMeasure. Neither of these properties
# exist yet, so they will be created.
ifcopenshell.api.run("pset.edit_qto", model, qto=qto, properties={"Length": 12, "NetVolume": 7.2})

# Setting to None will delete the quantity.
ifcopenshell.api.run("pset.edit_qto", model, qto=qto, properties={"Length": None})

# What if we wanted to manage our own properties? Let's create our
# own "Company Standard" property set templates. Notice how we
# prefix our property set with "Foo_", if our company name was "Foo"
# this would make sense. In this example, we say that our template
# only applies to walls and is for quantities.
template = ifcopenshell.api.run("pset_template.add_pset_template", model,
    name="Foo_Wall", template_type="QTO_OCCURRENCEDRIVEN", applicable_entity="IfcWall")

# Let's imagine we want all model authors to specify a length
# measurement for the portion of a wall that is overhanging.
prop = ifcopenshell.api.run("pset_template.add_prop_template", model, pset_template=template,
    name="OverhangLength", template_type="Q_LENGTH", primary_measure_type="IfcLengthMeasure")

# Now we can use our property set template to add our properties,
# and the data types will always match our template.
qto = ifcopenshell.api.run("pset.add_qto", model, product=wall, name="Foo_Wall")
ifcopenshell.api.run("pset.edit_qto", model,
    qto=qto, properties={"OverhangLength": 42.3}, pset_template=template)

# Here's a third scenario where we want to add arbitrary quantities
# that are not standardised by anything, not even our own custom
# templates.
qto = ifcopenshell.api.run("pset.add_qto", model, product=wall, name="Custom_Qto")
ifcopenshell.api.run("pset.edit_qto", model,
    qto=qto, properties={
        "SomeLength": model.createIfcLengthMeasure(42.3),
        "SomeArea": model.createIfcAreaMeasure(21.0)

# Editing existing quantities will retain their current data types
# if possible. So this will still be a length measure.
ifcopenshell.api.run("pset.edit_qto", model, qto=qto, properties={"SomeLength": 12.3})