4.13. foundations.nodes¶

nodes.py

Platform:: Windows, Linux, Mac Os X.
Description:: Defines various nodes and dag related classes.
Others:: Portions of the code from DAG by Simon Wittber: http://pypi.python.org/pypi/DAG/ and PyQt4 Model View Programming Tutorials by Yasin Uludag: http://www.yasinuludag.com/blog/?p=98

4.13.1. Module Attributes¶

foundations.nodes.LOGGER¶

4.13.2. Classes¶

class foundations.nodes.Attribute(name=None, value=None, **kwargs)[source]¶

Bases: foundations.dataStructures.Structure

Defines a storage object for the AbstractNode class attributes.

Initializes the class.

Usage:

>>> attribute = Attribute(name="My Attribute", value="My Value")
>>> attribute.name
u'My Attribute'
>>> attribute["name"]
u'My Attribute'
>>> attribute.value
u'My Value'
>>> attribute["value"]
u'My Value'

Parameters:	name (unicode) – Attribute name. value (object) – Attribute value. kwargs () – Keywords arguments.

name[source]¶

Property for self.__name attribute.

Returns:	Value.
Return type:	unicode

value[source]¶

Property for self.__value attribute.

Returns:	Value.
Return type:	object

class foundations.nodes.AbstractNode(name=None, **kwargs)[source]¶

Bases: foundations.dataStructures.Structure

Defines the base Node class.

Although it can be instancied directly that class is meant to be subclassed.

Note:	Doesn’t provide compositing capabilities, `AbstractCompositeNode` class must be used for that purpose.

Initializes the class.

Usage:

>>> nodeA = AbstractNode("MyNodeA")
>>> nodeA.identity
1
>>> nodeB = AbstractNode()
>>> nodeB.name
u'Abstract2'
>>> nodeB.identity
2

Parameters:	name (unicode) – Node name. kwargs () – Keywords arguments.

family[source]¶

Property for self.__family attribute.

Returns:	self.__family.
Return type:	unicode

nodesInstances[source]¶

Property for self.__nodesInstances attribute.

Returns:	self.__nodesInstances.
Return type:	WeakValueDictionary

identity[source]¶

Property for self.__identity attribute.

Returns:	self.__identity.
Return type:	unicode

name[source]¶

Property for self.__name attribute.

Returns:	self.__name.
Return type:	unicode

getNodeByIdentity(identity)[source]¶

Returns the Node with given identity.

Usage:

>>> nodeA = AbstractNode("MyNodeA")
>>> AbstractNode.getNodeByIdentity(1)
<AbstractNode object at 0x101043a80>

Parameters:	identity (int) – Node identity.
Returns:	Node.
Return type:	AbstractNode
Note:	Nodes identities are starting from ‘1’ to nodes instances count.

listAttributes()[source]¶

Returns the Node attributes names.

Usage:

>>>     nodeA = AbstractNode("MyNodeA", attributeA=Attribute(), attributeB=Attribute())
>>> nodeA.listAttributes()
['attributeB', 'attributeA']

Returns:	Attributes names.
Return type:	list

getAttributes()[source]¶

Returns the Node attributes.

Usage:

>>>     nodeA = AbstractNode("MyNodeA", attributeA=Attribute(value="A"), attributeB=Attribute(value="B"))
>>> nodeA.getAttributes()
[<Attribute object at 0x7fa471d3b5e0>, <Attribute object at 0x101e6c4a0>]

Returns:	Attributes.
Return type:	list

attributeExists(name)[source]¶

Returns if given attribute exists in the node.

Usage:

>>>     nodeA = AbstractNode("MyNodeA", attributeA=Attribute(), attributeB=Attribute())
>>> nodeA.attributeExists("attributeA")
True
>>> nodeA.attributeExists("attributeC")
False

Parameters:	name (unicode) – Attribute name.
Returns:	Attribute exists.
Return type:	bool

addAttribute(name, value)[source]¶

Adds given attribute to the node.

Usage:

>>>     nodeA = AbstractNode()
>>> nodeA.addAttribute("attributeA", Attribute())
True
>>> nodeA.listAttributes()
[u'attributeA']

Parameters:	name (unicode) – Attribute name. value (Attribute) – Attribute value.
Returns:	Method success.
Return type:	bool

removeAttribute(name)[source]¶

Removes given attribute from the node.

Usage:

>>>     nodeA = AbstractNode("MyNodeA", attributeA=Attribute(), attributeB=Attribute())
>>> nodeA.removeAttribute("attributeA")
True
>>> nodeA.listAttributes()
['attributeB']

Parameters:	name (unicode) – Attribute name.
Returns:	Method success.
Return type:	bool

class foundations.nodes.AbstractCompositeNode(name=None, parent=None, children=None, **kwargs)[source]¶

Bases: foundations.nodes.AbstractNode

Defines the base composite Node class.

It provides compositing capabilities allowing the assembly of graphs and various trees structures.

Initializes the class.

Parameters:	name (unicode) – Node name. parent (AbstractNode or AbstractCompositeNode) – Node parent. children (list) – Children. kwargs () – Keywords arguments.
Note:	`pickle.HIGHEST_PROTOCOL` must be used to pickle `foundations.nodes.AbstractCompositeNode` class.

parent[source]¶

Property for self.__parent attribute.

Returns:	self.__parent.
Return type:	AbstractNode or AbstractCompositeNode

children[source]¶

Property for self.__children attribute.

Returns:	self.__children.
Return type:	list

child(index)[source]¶

Returns the child associated with given index.

Usage:

>>> nodeB = AbstractCompositeNode("MyNodeB")
>>> nodeC = AbstractCompositeNode("MyNodeC")
>>> nodeA = AbstractCompositeNode("MyNodeA", children=[nodeB, nodeC])
>>> nodeA.child(0)
<AbstractCompositeNode object at 0x10107b6f0>
>>> nodeA.child(0).name
u'MyNodeB'

Parameters:	index (int) – Child index.
Returns:	Child node.
Return type:	AbstractNode or AbstractCompositeNode or Object

indexOf(child)[source]¶

Returns the given child index.

Usage:

>>> nodeA = AbstractCompositeNode("MyNodeA")
>>> nodeB = AbstractCompositeNode("MyNodeB", nodeA)
>>> nodeC = AbstractCompositeNode("MyNodeC", nodeA)
>>> nodeA.indexOf(nodeB)
0
>>> nodeA.indexOf(nodeC)
1

Parameters:	child (AbstractNode or AbstractCompositeNode or Object) – Child node.
Returns:	Child index.
Return type:	int

row()[source]¶

Returns the Node row.

Usage:

>>> nodeA = AbstractCompositeNode("MyNodeA")
>>> nodeB = AbstractCompositeNode("MyNodeB", nodeA)
>>> nodeC = AbstractCompositeNode("MyNodeC", nodeA)
>>> nodeB.row()
0
>>> nodeC.row()
1       

Returns:	Node row.
Return type:	int

addChild(child)[source]¶

Adds given child to the node.

Usage:

>>> nodeA = AbstractCompositeNode("MyNodeA")
>>> nodeB = AbstractCompositeNode("MyNodeB")
>>> nodeA.addChild(nodeB)
True
>>> nodeA.children
[<AbstractCompositeNode object at 0x10107afe0>]

Parameters:	child (AbstractNode or AbstractCompositeNode or Object) – Child node.
Returns:	Method success.
Return type:	bool

removeChild(index)[source]¶

Removes child at given index from the Node children.

Usage:

>>> nodeA = AbstractCompositeNode("MyNodeA")
>>> nodeB = AbstractCompositeNode("MyNodeB", nodeA)
>>> nodeC = AbstractCompositeNode("MyNodeC", nodeA)
>>> nodeA.removeChild(1)
True
>>> [child.name for child in nodeA.children]
[u'MyNodeB']

Parameters:	index (int) – Node index.
Returns:	Removed child.
Return type:	AbstractNode or AbstractCompositeNode or Object

insertChild(child, index)[source]¶

Inserts given child at given index.

Usage:

>>> nodeA = AbstractCompositeNode("MyNodeA")
>>> nodeB = AbstractCompositeNode("MyNodeB", nodeA)
>>> nodeC = AbstractCompositeNode("MyNodeC", nodeA)
>>> nodeD = AbstractCompositeNode("MyNodeD")
>>> nodeA.insertChild(nodeD, 1)
True
>>> [child.name for child in nodeA.children]
[u'MyNodeB', u'MyNodeD', u'MyNodeC']

Parameters:	child (AbstractNode or AbstractCompositeNode or Object) – Child node. index (int) – Insertion index.
Returns:	Method success.
Return type:	bool

hasChildren()[source]¶

Returns if the Node has children.

Usage:

>>> nodeA = AbstractCompositeNode("MyNodeA")
>>> nodeA.hasChildren()
False

Returns:	Children count.
Return type:	int

childrenCount()[source]¶

Returns the children count.

Usage:

>>> nodeA = AbstractCompositeNode("MyNodeA")
>>> nodeB = AbstractCompositeNode("MyNodeB", nodeA)
>>> nodeC = AbstractCompositeNode("MyNodeC", nodeA)
>>> nodeA.childrenCount()
2

Returns:	Children count.
Return type:	int

sortChildren(attribute=None, reverseOrder=False)[source]¶

Sorts the children using either the given attribute or the Node name.

Parameters:	attribute (unicode) – Attribute name used for sorting. reverseOrder (bool) – Sort in reverse order.
Returns:	Method success.
Return type:	bool

findChildren(pattern=u'.*', flags=0, candidates=None)[source]¶

Finds the children matching the given patten.

Usage:

>>> nodeA = AbstractCompositeNode("MyNodeA")
>>> nodeB = AbstractCompositeNode("MyNodeB", nodeA)
>>> nodeC = AbstractCompositeNode("MyNodeC", nodeA)
>>> nodeA.findChildren("c", re.IGNORECASE)
[<AbstractCompositeNode object at 0x101078040>]

Parameters:	pattern (unicode) – Matching pattern. flags (int) – Matching regex flags. candidates (list) – Matching candidates.
Returns:	Matching children.
Return type:	list

findFamily(pattern=u'.*', flags=0, node=None)[source]¶

Returns the Nodes from given family.

Parameters:	pattern (unicode) – Matching pattern. flags (int) – Matching regex flags. node (AbstractNode or AbstractCompositeNode or Object) – Node to start walking from.
Returns:	Family nodes.
Return type:	list

listNode(tabLevel=-1)[source]¶

Lists the current Node and its children.

Usage:

>>> nodeA = AbstractCompositeNode("MyNodeA")
>>> nodeB = AbstractCompositeNode("MyNodeB", nodeA)
>>> nodeC = AbstractCompositeNode("MyNodeC", nodeA)
>>> print nodeA.listNode()
|----'MyNodeA'
                |----'MyNodeB'
                |----'MyNodeC'

Parameters:	tabLevel (int) – Tab level.
Returns:	Node listing.
Return type:	unicode