spaCy/spacy/pattern/pattern.py
Raphaël Bournhonesque 1849a110e3 Improve logging
2017-06-11 18:31:19 +02:00

319 lines
10 KiB
Python

# coding: utf-8
import logging
from collections import defaultdict
logger = logging.getLogger(__name__)
class Tree(object):
def __init__(self):
self.adjacency = defaultdict(dict)
self.nodes = {}
def __getitem__(self, item):
return self.nodes[item]
def add_node(self, node, attr_dict=None):
attr_dict = attr_dict or {}
self.nodes[node] = attr_dict
def add_edge(self, u, v, dep=None):
if u not in self.nodes or v not in self.nodes:
raise ValueError("Each node must be defined before adding an edge.")
self.adjacency[u][v] = dep
def number_of_nodes(self):
return len(self)
def __len__(self):
return len(self.nodes)
def number_of_edges(self):
return sum(len(adj_dict) for adj_dict in self.adjacency.values())
def edges_iter(self, origin=None, data=True):
nbunch = (self.adjacency.items() if origin is None
else [(origin, self.adjacency[origin])])
for u, nodes in nbunch:
for v, dep in nodes.items():
if data:
yield (u, v, dep)
else:
yield (u, v)
def nodes_iter(self):
for node in self.nodes.keys():
yield node
def is_connected(self):
if len(self) == 0:
raise ValueError('Connectivity is undefined for the null graph.')
return len(set(self._plain_bfs(next(self.nodes_iter()),
undirected=True))) == len(self)
def _plain_bfs(self, source, undirected=False):
"""A fast BFS node generator.
:param: source: the source node
"""
seen = set()
next_level = {source}
while next_level:
this_level = next_level
next_level = set()
for v in this_level:
if v not in seen:
yield v
seen.add(v)
next_level.update(self.adjacency[v].keys())
if undirected:
for n, adj in self.adjacency.items():
if v in adj.keys():
next_level.add(n)
class DependencyPattern(Tree):
@property
def root_node(self):
if self.number_of_nodes() == 1:
# if the graph has a single node, it is the root
return next(iter(self.nodes.keys()))
if not self.is_connected():
return None
in_node = set()
out_node = set()
for u, v in self.edges_iter(data=False):
in_node.add(v)
out_node.add(u)
try:
return list(out_node.difference(in_node))[0]
except IndexError:
return None
class DependencyTree(Tree):
def __init__(self, doc):
super(DependencyTree, self).__init__()
for token in doc:
self.nodes[token.i] = token
if token.head.i != token.i:
# inverse the dependency to have an actual tree
self.adjacency[token.head.i][token.i] = token.dep_
def __getitem__(self, item):
return self.nodes[item]
def match_nodes(self, attr_dict, **kwargs):
results = []
for token_idx, token in self.nodes.items():
if match_token(token, attr_dict, **kwargs):
results.append(token_idx)
return results
def match(self, pattern):
"""Return a list of matches between the given
:class:`DependencyPattern` and `self` if any, or None.
:param pattern: a :class:`DependencyPattern`
"""
pattern_root_node = pattern.root_node
pattern_root_node_attr = pattern[pattern_root_node]
dep_root_nodes = self.match_nodes(pattern_root_node_attr)
if not dep_root_nodes:
logger.debug("No node matches the pattern root "
"'{}'".format(pattern_root_node_attr))
matches = []
for candidate_root_node in dep_root_nodes:
match_list = subtree_in_graph(candidate_root_node, self,
pattern_root_node, pattern)
for mapping in match_list:
match = PatternMatch(mapping, pattern, self)
matches.append(match)
return matches
class PatternMatch(object):
def __init__(self, mapping, pattern, tree):
for pattern_node_id, tree_node_id in mapping.items():
mapping[pattern_node_id] = tree[tree_node_id]
self.mapping = mapping
self.pattern = pattern
self.tree = tree
self.alias_map = {}
for pattern_node_id in self.mapping:
pattern_node = self.pattern[pattern_node_id]
alias = pattern_node.get('_alias')
if alias:
self.alias_map[alias] = self.mapping[pattern_node_id]
def __repr__(self):
return "<Pattern Match: {} node>".format(len(self.mapping))
def __getitem__(self, item):
return self.alias_map[item]
def subtree_in_graph(dep_tree_node, dep_tree, pattern_node, pattern):
"""Return a list of matches of `pattern` as a subtree of `dep_tree`.
:param dep_tree_node: the token (identified by its index) to start from
(int)
:param dep_tree: a :class:`DependencyTree`
:param pattern_node: the pattern node to start from
:param pattern: a :class:`DependencyPattern`
:return: found matches (list)
"""
results = []
association_dict = {pattern_node: dep_tree_node}
_subtree_in_graph(dep_tree_node, dep_tree, pattern_node,
pattern, results=results,
association_dict=association_dict)
results = results or []
return results
def _subtree_in_graph(dep_tree_node, dep_tree, pattern_node, pattern,
association_dict=None, results=None):
token = dep_tree[dep_tree_node]
logger.debug("Starting from token '{}'".format(token.orth_))
adjacent_edges = list(pattern.edges_iter(origin=pattern_node))
if adjacent_edges:
for (_, adjacent_pattern_node,
dep) in adjacent_edges:
adjacent_pattern_node_attr = pattern[adjacent_pattern_node]
logger.debug("Exploring relation {} -[{}]-> {} from "
"pattern".format(pattern[pattern_node],
dep,
adjacent_pattern_node_attr))
adjacent_nodes = find_adjacent_nodes(dep_tree,
dep_tree_node,
dep,
adjacent_pattern_node_attr)
if not adjacent_nodes:
logger.debug("No adjacent nodes in dep_tree satisfying these "
"conditions.")
return None
for adjacent_node in adjacent_nodes:
logger.debug("Found adjacent node '{}' in "
"dep_tree".format(dep_tree[adjacent_node].orth_))
association_dict[adjacent_pattern_node] = adjacent_node
recursive_return = _subtree_in_graph(adjacent_node,
dep_tree,
adjacent_pattern_node,
pattern,
association_dict,
results=results)
if recursive_return is None:
# No Match
return None
association_dict, results = recursive_return
else:
if len(association_dict) == pattern.number_of_nodes():
logger.debug("Add to results: {}".format(association_dict))
results.append(dict(association_dict))
else:
logger.debug("{} nodes in subgraph, only {} "
"mapped".format(pattern.number_of_nodes(),
len(association_dict)))
logger.debug("Return intermediate: {}".format(association_dict))
return association_dict, results
def find_adjacent_nodes(dep_tree, node, target_dep, node_attributes):
"""Find nodes adjacent to ``node`` that fulfill specified attributes
values on edge and node.
:param dep_tree: a :class:`DependencyTree`
:param node: initial node to search from
:param target_dep: edge attributes that must be fulfilled (pair-value)
:type target_dep: dict
:param node_attributes: node attributes that must be fulfilled (pair-value)
:type node_attributes: dict
:return: adjacent nodes that fulfill the given criteria (list)
"""
results = []
for _, adj_node, adj_dep in dep_tree.edges_iter(origin=node):
adj_token = dep_tree[adj_node]
if (match_edge(adj_dep, target_dep)
and match_token(adj_token, node_attributes)):
results.append(adj_node)
return results
def match_edge(token_dep, target_dep):
if target_dep is None:
return True
if hasattr(target_dep, 'match'):
return target_dep.match(token_dep) is not None
if token_dep == target_dep:
return True
return False
def match_token(token,
target_attributes,
ignore_special_key=True,
lower=True):
bind_map = {
'word': lambda t: t.orth_,
'lemma': lambda t: t.lemma_,
'ent': lambda t: t.ent_type_,
}
for target_key, target_value in target_attributes.items():
is_special_key = target_key[0] == '_'
if ignore_special_key and is_special_key:
continue
if lower and hasattr(target_value, 'lower'):
target_value = target_value.lower()
if target_key in bind_map:
token_attr = bind_map[target_key](token)
if lower:
token_attr = token_attr.lower()
if hasattr(target_value, 'match'): # if it is a compiled regex
if target_value.match(token_attr) is None:
break
else:
if not token_attr == target_value:
break
else:
raise ValueError("Unknown key: '{}'".format(target_key))
else: # the loop was not broken
return True
return False