Package nltk :: Package parse :: Module dependencygraph :: Class DependencyGraph

type DependencyGraph

object --+
         |
        DependencyGraph

A container for the nodes and labelled edges of a dependency structure.

Instance Methods

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__init__(self, tree_str=None)
We place a dummy 'top' node in the first position in the nodelist, since the root node is often assigned '0' as its head.

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remove_by_address(self, address)
Removes the node with the given address.

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redirect_arcs(self, originals, redirect)
Redirects arcs to any of the nodes in the originals list to the redirect node address.

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add_arc(self, head_address, mod_address)
Adds an arc from the node specified by head_address to the node specified by the mod address.

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connect_graph(self)
Fully connects all non-root nodes.

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get_by_address(self, node_address)
Returns the node with the given address.

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contains_address(self, node_address)
Returns true if the graph contains a node with the given node address, false otherwise.

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__str__(self)

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__repr__(self)

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left_children(self, node_index)
Returns the number of left children under the node specified by the given address.

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right_children(self, node_index)
Returns the number of right children under the node specified by the given address.

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add_node(self, node)

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_parse(self, input)

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_word(self, node, filter=True)

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_tree(self, i)
Recursive function for turning dependency graphs into NLTK trees.

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tree(self)
Starting with the root node, build a dependency tree using the NLTK Tree constructor. source code

_hd(self, i)

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_rel(self, i)

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contains_cycle(self)

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get_cycle_path(self, curr_node, goal_node_index)

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str

to_conll(self, style)
The dependency graph in CoNLL format.

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Static Methods

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load(file)

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_normalize(line)
Deal with lines in which spaces are used rather than tabs.

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Method Details

[hide private]

init(self, tree_str=None)
(Constructor)

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We place a dummy 'top' node in the first position in the nodelist, since the root node is often assigned '0' as its head. This also means that the indexing of the nodelist corresponds directly to the Malt-TAB format, which starts at 1.