Expression Class

class NXOpen.Expression

Bases: NXOpen.NXObject

Represents an expression.

To create a new instance of this class, use NXOpen.ExpressionCollection.CreateWithUnits()

New in version NX3.0.0.

Properties

Property	Description
BooleanValue	Returns the boolean value of the expression.
Description	Returns the description of the expression.
Equation	Returns the equation of the expression in the form: name = right_hand_side.
IntegerValue	Returns the integer value of the expression.
IsGeometricExpression	Returns whether the expression is a geometric expression.
IsInterpartExpression	Returns whether the expression is an interpart expression.
IsMeasurementExpression	Returns whether the expression is owned by a measurement.
IsNoEdit	Returns or sets whether the expression is edit locked.
IsNoUpdate	Returns or sets whether the expression is update locked.
IsOccurrence	Returns whether this object is an occurrence or not.
IsUserLocked	Returns or sets whether the expression is user locked.
JournalIdentifier	Returns the identifier that would be recorded in a journal for this object.
Name	Returns the custom name of the object.
OwningComponent	Returns the owning component, if this object is an occurrence.
OwningPart	Returns the owning part of this object
PointValue	Returns the point value of the expression.
Prototype	Returns the prototype of this object if it is an occurrence.
RightHandSide	Returns or sets the right hand side of the expression.
StringValue	Returns the string value of the expression.
Tag	Returns the Tag for this object.
Type	Returns the type of the expression.
Units	Returns or sets the units for the expression.
Value	Returns or sets the value of the expression in base units.
VectorValue	Returns the vector value of the expression.

Methods

Method	Description
CreateAttributeIterator	Create an attribute iterator @return A new attribute iterator object
DeleteAllAttributesByType	Deletes all attributes of a specific type.
DeleteAttributeByTypeAndTitle	Deletes an attribute by type and title.
DeleteUserAttribute	Deletes the first attribute encountered with the given Type, Title.
DeleteUserAttributes	Deletes the attributes on the object, if any, that satisfy the given iterator
EditComment	Changes the comment.
FindObject	Finds the NXOpen.NXObject with the given identifier as recorded in a journal.
GetAttributeTitlesByType	Gets all the attribute titles of a specific type.
GetBooleanUserAttribute	Gets a boolean attribute by Title and array Index.
GetComputationalTimeUserAttribute	Gets a time attribute by Title and array Index.
GetDescriptor	Returns the descriptor for the expression, or None if there is no descriptor.
GetIntegerAttribute	Gets an integer attribute by title.
GetIntegerUserAttribute	Gets an integer attribute by Title and array Index.
GetInterpartExpressionNames	The source part name and source expression name of the interpart expression
GetListValue	Returns the list value of the expression.
GetNextUserAttribute	Gets the next attribute encountered on the object, if any, that satisfies the given iterator.
GetOwningFeature	Returns the feature that created the supplied expression.
GetOwningRpoFeature	Returns the feature whose rpo_transform created the supplied positioning dimension expression.
GetRealAttribute	Gets a real attribute by title.
GetRealUserAttribute	Gets a real attribute by Title and array Index.
GetReferenceAttribute	Gets the reference string (not the calculated value) of a string attribute that uses a reference string.
GetReferencingExpressions	Returns all the referencing expressions of the expression @return
GetStringAttribute	Gets a string attribute value by title.
GetStringUserAttribute	Gets a string attribute by Title and array Index.
GetTimeAttribute	Gets a time attribute by title.
GetTimeUserAttribute	Gets a time attribute by Title and array Index.
GetUserAttribute	Gets the first attribute encountered on the object, if any, with a given Title, Type and array Index.
GetUserAttributeAsString	Gets the first attribute encountered on the object, if any, with a given title, type and array index.
GetUserAttributeCount	Gets the count of set attributes on the object, if any, that satisfy the given iterator.
GetUserAttributeLock	Determine the lock of the given attribute.
GetUserAttributeSize	Gets the size of the first attribute encountered on the object, if any, with a given Title and Type.
GetUserAttributeSourceObjects	Returns an array of objects from which this object presents attributes.
GetUserAttributes	Gets all the attributes that have been set on the given object, if any, that satisfy the given iterator.
GetUserAttributesAsStrings	Gets all the attributes that have been set on the given object.
GetUsingFeatures	Returns an array of the features that use the supplied expression.
GetValueUsingUnits	Get the value of the expression, in either base units or the expression’s units.
HasUserAttribute	Determines if an attribute exists on the object, that satisfies the given iterator @return
Print	Prints a representation of this object to the system log file.
SetAttribute	Creates or modifies an integer attribute.
SetBooleanUserAttribute	Creates or modifies a boolean attribute with the option to update or not.
SetName	Sets the custom name of the object.
SetReferenceAttribute	Creates or modifies a string attribute which uses a reference string.
SetTimeAttribute	Creates or modifies a time attribute.
SetTimeUserAttribute	Creates or modifies a time attribute with the option to update or not.
SetUserAttribute	Creates or modifies an attribute with the option to update or not.
SetUserAttributeLock	Lock or unlock the given attribute.

Enumerations

ExpressionUnitsOption Enumeration

Indicates the units to use when getting an expression’s value.

Property Detail

BooleanValue

Expression.BooleanValue

Returns the boolean value of the expression.

This must only be used on boolean expressions.

-------------------------------------

Getter Method

Signature BooleanValue()

Returns: Return type:bool

New in version NX6.0.0.

License requirements: None.

Description

Expression.Description

Returns the description of the expression.

This can be used to get the “A”::x formatted name for interpart expressions.

-------------------------------------

Getter Method

Signature Description()

Returns: Return type:str

New in version NX5.0.2.

License requirements: None.

Equation

Expression.Equation

Returns the equation of the expression in the form: name = right_hand_side.

-------------------------------------

Getter Method

Signature Equation()

Returns: Return type:str

New in version NX3.0.0.

License requirements: None.

IntegerValue

Expression.IntegerValue

Returns the integer value of the expression.

This must only be used on integer expressions.

-------------------------------------

Getter Method

Signature IntegerValue()

Returns: Return type:int

New in version NX6.0.0.

License requirements: None.

IsGeometricExpression

Expression.IsGeometricExpression

Returns whether the expression is a geometric expression.

-------------------------------------

Getter Method

Signature IsGeometricExpression()

Returns: Return type:bool

New in version NX4.0.0.

License requirements: None.

IsInterpartExpression

Expression.IsInterpartExpression

Returns whether the expression is an interpart expression.

-------------------------------------

Getter Method

Signature IsInterpartExpression()

Returns: Return type:bool

New in version NX11.0.0.

License requirements: None.

IsMeasurementExpression

Expression.IsMeasurementExpression

Returns whether the expression is owned by a measurement.

-------------------------------------

Getter Method

Signature IsMeasurementExpression()

Returns: Return type:bool

New in version NX5.0.0.

License requirements: None.

IsNoEdit

Expression.IsNoEdit

Returns or sets whether the expression is edit locked.

If this property is false, then the expression can be edited. (This is the default state for newly created expressions.) If this property is true, then the expression cannot be edited. This corresponds to the interactive option RMB Lock Formula/RMB Unlock Formula.

-------------------------------------

Getter Method

Signature IsNoEdit()

Returns: Return type:bool

New in version NX8.5.0.

License requirements: None.

-------------------------------------

Setter Method

Signature IsNoEdit(isNoEdit)

Parameters:isNoEdit (bool) –

New in version NX8.5.0.

License requirements: None.

IsNoUpdate

Expression.IsNoUpdate

Returns or sets whether the expression is update locked.

If this property is false, then the expression can update. (This is the default state for newly created expressions.) If this property is true, then the expression cannot update.

-------------------------------------

Getter Method

Signature IsNoUpdate()

Returns: Return type:bool

New in version NX10.0.0.

License requirements: None.

-------------------------------------

Setter Method

Signature IsNoUpdate(isNoUpdate)

Parameters:isNoUpdate (bool) –

New in version NX10.0.0.

License requirements: None.

IsOccurrence

Expression.IsOccurrence

Returns whether this object is an occurrence or not.

-------------------------------------

Getter Method

Signature IsOccurrence()

Returns:This object is an occurrence Return type:bool

New in version NX3.0.0.

License requirements: None.

IsUserLocked

Expression.IsUserLocked

Returns or sets whether the expression is user locked.

If this property is false, then the expression can be over-ridden from another part. (This is the default state for newly created expressions.) If this property is true, you are not allowed to over-ride it. This corresponds to the interactive option RMB Toggle Interpart Override Lock.

Note that if an expression is currently over-ridden, you cannot set its lock property. In this instance, an exception will be thrown.

-------------------------------------

Getter Method

Signature IsUserLocked()

Returns: Return type:bool

New in version NX4.0.0.

License requirements: None.

-------------------------------------

Setter Method

Signature IsUserLocked(isLocked)

Parameters:isLocked (bool) –

New in version NX4.0.0.

License requirements: None.

JournalIdentifier

Expression.JournalIdentifier

Returns the identifier that would be recorded in a journal for this object.

This may not be the same across different releases of the software.

-------------------------------------

Getter Method

Signature JournalIdentifier()

Returns: Return type:str

New in version NX3.0.0.

License requirements: None.

Name

Expression.Name

Returns the custom name of the object.

-------------------------------------

Getter Method

Signature Name()

Returns: Return type:str

New in version NX3.0.0.

License requirements: None.

OwningComponent

Expression.OwningComponent

Returns the owning component, if this object is an occurrence.

-------------------------------------

Getter Method

Signature OwningComponent()

Returns: Return type:NXOpen.Assemblies.Component

New in version NX3.0.0.

License requirements: None.

OwningPart

Expression.OwningPart

Returns the owning part of this object

-------------------------------------

Getter Method

Signature OwningPart()

Returns:The owning part of this object or null if it does not have an owner Return type:NXOpen.BasePart

New in version NX3.0.0.

License requirements: None.

PointValue

Expression.PointValue

Returns the point value of the expression.

This must only be used on point expressions.

-------------------------------------

Getter Method

Signature PointValue()

Returns: Return type:NXOpen.Point3d

New in version NX6.0.0.

License requirements: None.

Prototype

Expression.Prototype

Returns the prototype of this object if it is an occurrence.

-------------------------------------

Getter Method

Signature Prototype()

Returns:The prototype of this object or null if this object is not an occurrence Return type:NXOpen.INXObject

New in version NX3.0.0.

License requirements: None.

RightHandSide

Expression.RightHandSide

Returns or sets the right hand side of the expression.

When setting the property, changes are not applied to the system until Update.DoUpdate() is called

-------------------------------------

Getter Method

Signature RightHandSide()

Returns: Return type:str

New in version NX3.0.0.

License requirements: None.

-------------------------------------

Setter Method

Signature RightHandSide(rightHandSide)

Parameters:rightHandSide (str) –

New in version NX3.0.0.

License requirements: None.

StringValue

Expression.StringValue

Returns the string value of the expression.

This must only be used on string expressions.

-------------------------------------

Getter Method

Signature StringValue()

Returns: Return type:str

New in version NX5.0.0.

License requirements: None.

Type

Expression.Type

Returns the type of the expression.

-------------------------------------

Getter Method

Signature Type()

Returns:a text string for the expression type Return type:str

New in version NX5.0.0.

License requirements: None.

Units

Expression.Units

Returns or sets the units for the expression.

This must only be used on number expressions.

-------------------------------------

Getter Method

Signature Units()

Returns:None if the expression has no units Return type:NXOpen.Unit

New in version NX4.0.0.

License requirements: None.

-------------------------------------

Setter Method

Signature Units(unitType)

Parameters:unitType (NXOpen.Unit) –

New in version NX5.0.0.

License requirements: None.

Value

Expression.Value

Returns or sets the value of the expression in base units.

This method must only be used on number expressions. When setting the value, any formula in the expression is replaced by a numeric value, even if the value is the same as the value that the formula evaluates to.

-------------------------------------

Getter Method

Signature Value()

Returns: Return type:float

New in version NX3.0.0.

License requirements: None.

-------------------------------------

Setter Method

Signature Value(expressionValue)

Parameters:expressionValue (float) –

New in version NX6.0.1.

License requirements: None.

VectorValue

Expression.VectorValue

Returns the vector value of the expression.

This must only be used on vector expressions.

-------------------------------------

Getter Method

Signature VectorValue()

Returns: Return type:NXOpen.Vector3d

New in version NX6.0.0.

License requirements: None.

Method Detail

EditComment

Expression.EditComment

Changes the comment.

Signature EditComment(newComment)

Parameters:newComment (str) – comment

New in version NX4.0.0.

License requirements: None.

FindObject

Expression.FindObject

Finds the NXOpen.NXObject with the given identifier as recorded in a journal.

An object may not return the same value as its JournalIdentifier in different versions of the software. However newer versions of the software should find the same object when FindObject is passed older versions of its journal identifier. In general, this method should not be used in handwritten code and exists to support record and playback of journals.

An exception will be thrown if no object can be found with the given journal identifier.

Signature FindObject(journalIdentifier)

Parameters:journalIdentifier (str) – Journal identifier of the object Returns: Return type:NXOpen.INXObject

New in version NX3.0.0.

License requirements: None.

GetDescriptor

Expression.GetDescriptor

Returns the descriptor for the expression, or None if there is no descriptor.

Currently, only feature expressions have descriptors.

Signature GetDescriptor()

Returns:Expression descriptor. Return type:str

New in version NX4.0.0.

License requirements: None.

GetInterpartExpressionNames

Expression.GetInterpartExpressionNames

The source part name and source expression name of the interpart expression

Signature GetInterpartExpressionNames()

Returns:a tuple Return type:A tuple consisting of (partName, expName). partName is a str. expName is a str.

New in version NX10.0.0.

License requirements: None.

GetListValue

Expression.GetListValue

Returns the list value of the expression.

This must only be used on list expressions.

Signature GetListValue()

Returns: Return type:Variant

New in version NX6.0.0.

License requirements: None.

GetOwningFeature

Expression.GetOwningFeature

Returns the feature that created the supplied expression.

This is the feature that created it during feature creation. For example, the expression “p0 = x” is owned by feature “BLOCK(0)”.

This works with both normal expressions and expressions created by the geometric expression feature.

Signature GetOwningFeature()

Returns:owning feature or None Return type:NXOpen.Features.Feature

New in version NX4.0.0.

License requirements: None.

GetOwningRpoFeature

Expression.GetOwningRpoFeature

Returns the feature whose rpo_transform created the supplied positioning dimension expression.

This is the feature that created it during positioning the feature. For example, the expression “p0 = x” is owned by the Transform of feature “Boss(2)”.

This works with expressions created by the feature with rpo.

Signature GetOwningRpoFeature()

Returns:owning rpo feature or None Return type:NXOpen.Features.Feature

New in version NX7.5.0.

License requirements: None.

GetReferencingExpressions

Expression.GetReferencingExpressions

Returns all the referencing expressions of the expression

Signature GetReferencingExpressions()

Returns: Return type:list of NXOpen.Expression

New in version NX8.0.0.

License requirements: None.

GetUsingFeatures

Expression.GetUsingFeatures

Returns an array of the features that use the supplied expression.

Signature GetUsingFeatures()

Returns:array of features, or empty array Return type:list of NXOpen.Features.Feature

New in version NX4.0.0.

License requirements: None.

GetValueUsingUnits

Expression.GetValueUsingUnits

Get the value of the expression, in either base units or the expression’s units.

This method must only be used on number expressions.

Signature GetValueUsingUnits(unitsOption)

Parameters:unitsOption (NXOpen.ExpressionUnitsOption) – use base units or expression units Returns: Return type:float

New in version NX4.0.0.

License requirements: None.

Print

Expression.Print

Prints a representation of this object to the system log file.

Signature Print()

New in version NX3.0.0.

License requirements: None.

SetName

Expression.SetName

Sets the custom name of the object.

NOTE: This method should not be used to edit a read-only object such as a Mirrored PMI object. If it is, the changes will be overridden when the part is updated.

Signature SetName(name)

Parameters:name (str) –

New in version NX3.0.0.

License requirements: None.