"""
## 44. 係り受け木の可視化[Permalink](https://nlp100.github.io/ja/ch05.html#44-係り受け木の可視化)
与えられた文の係り受け木を有向グラフとして可視化せよ．可視化には，[Graphviz](http://www.graphviz.org/)等を用いるとよい．
"""
from collections import defaultdict
from typing import List, Tuple
import pydot
def read_file(fpath: str) -> List[List[str]]:
"""Get clear format of parsed sentences.
Args:
fpath (str): File path.
Returns:
List[List[str]]: List of sentences, and each sentence contains a word list.
e.g. result[1]:
['* 0 2D 0/0 -0.764522',
'\u3000\t記号,空白,*,*,*,*,\u3000,\u3000,\u3000',
'* 1 2D 0/1 -0.764522',
'吾輩\t名詞,代名詞,一般,*,*,*,吾輩,ワガハイ,ワガハイ',
'は\t助詞,係助詞,*,*,*,*,は,ハ,ワ',
'* 2 -1D 0/2 0.000000',
'猫\t名詞,一般,*,*,*,*,猫,ネコ,ネコ',
'で\t助動詞,*,*,*,特殊・ダ,連用形,だ,デ,デ',
'ある\t助動詞,*,*,*,五段・ラ行アル,基本形,ある,アル,アル',
'。\t記号,句点,*,*,*,*,。,。,。']
"""
with open(fpath, mode="rt", encoding="utf-8") as f:
sentences = f.read().split("EOS\n")
return [sent.strip().split("\n") for sent in sentences if sent.strip() != ""]
class Morph:
"""Morph information for each token.
Args:
data (dict): A dictionary contains necessary information.
Attributes:
surface (str): 表層形（surface）
base (str): 基本形（base）
pos (str): 品詞（base）
pos1 (str): 品詞細分類1（pos1
"""
def __init__(self, data):
self.surface = data["surface"]
self.base = data["base"]
self.pos = data["pos"]
self.pos1 = data["pos1"]
def __repr__(self):
return f"Morph({self.surface})"
def __str__(self):
return "surface[{}]\tbase[{}]\tpos[{}]\tpos1[{}]".format(
self.surface, self.base, self.pos, self.pos1
)
class Chunk:
"""Containing information for Clause/phrase.
Args:
data (dict): A dictionary contains necessary information.
Attributes:
chunk_id (str): The number of clause chunk (文節番号).
morphs List[Morph]: Morph (形態素) list.
dst (str): The index of dependency target (係り先文節インデックス番号).
srcs (List[str]): The index list of dependency source. (係り元文節インデックス番号).
"""
def __init__(self, chunk_id, dst):
self.id = chunk_id
self.morphs = []
self.dst = dst
self.srcs = []
def __repr__(self):
return "Chunk( id: {}, dst: {}, srcs: {}, morphs: {} )".format(
self.id, self.dst, self.srcs, self.morphs
)
def get_surface(self) -> str:
"""Concatenate morph surfaces in a chink.
Args:
chunk (Chunk): e.g. Chunk( id: 0, dst: 5, srcs: [], morphs: [Morph(吾輩), Morph(は)]
Return:
e.g. '吾輩は'
"""
morphs = self.morphs
res = ""
for morph in morphs:
if morph.pos != "記号":
res += morph.surface
return res
def validate_pos(self, pos: str) -> bool:
"""Return Ture if '名詞' or '動詞' in chunk's morphs. Otherwise, return False."""
morphs = self.morphs
return any([morph.pos == pos for morph in morphs])
def convert_sent_to_chunks(sent: List[str]) -> List[Morph]:
"""Extract word and convert to morph.
Args:
sent (List[str]): A sentence contains a word list.
e.g. sent:
['* 0 1D 0/1 0.000000',
'吾輩\t名詞,代名詞,一般,*,*,*,吾輩,ワガハイ,ワガハイ',
'は\t助詞,係助詞,*,*,*,*,は,ハ,ワ',
'* 1 -1D 0/2 0.000000',
'猫\t名詞,一般,*,*,*,*,猫,ネコ,ネコ',
'で\t助動詞,*,*,*,特殊・ダ,連用形,だ,デ,デ',
'ある\t助動詞,*,*,*,五段・ラ行アル,基本形,ある,アル,アル',
'。\t記号,句点,*,*,*,*,。,。,。']
Parsing format:
e.g. "* 0 1D 0/1 0.000000"
| カラム | 意味 |
| :----: | :----------------------------------------------------------- |
| 1 | 先頭カラムは`*`。係り受け解析結果であることを示す。 |
| 2 | 文節番号（0から始まる整数） |
| 3 | 係り先番号＋`D` |
| 4 | 主辞/機能語の位置と任意の個数の素性列 |
| 5 | 係り関係のスコア。係りやすさの度合で、一般に大きな値ほど係りやすい。 |
Returns:
List[Chunk]: List of chunks.
"""
chunks = []
chunk = None
srcs = defaultdict(list)
for i, word in enumerate(sent):
if word[0] == "*":
# Add chunk to chunks
if chunk is not None:
chunks.append(chunk)
# eNw Chunk beggin
chunk_id = word.split(" ")[1]
dst = word.split(" ")[2].rstrip("D")
chunk = Chunk(chunk_id, dst)
srcs[dst].append(chunk_id) # Add target->source to mapping list
else: # Add Morch to chunk.morphs
features = word.split(",")
dic = {
"surface": features[0].split("\t")[0],
"base": features[6],
"pos": features[0].split("\t")[1],
"pos1": features[1],
}
chunk.morphs.append(Morph(dic))
if i == len(sent) - 1: # Add the last chunk
chunks.append(chunk)
# Add srcs to each chunk
for chunk in chunks:
chunk.srcs = list(srcs[chunk.id])
return chunks
def get_edges(chunks: List[Chunk]) -> List[Tuple[str, str]]:
"""Get edges from sentence chunks.
Args:
chunks (List[Chunk]): A sentence contains many chunks.
e.g. [Chunk( id: 0, dst: 5, srcs: [], morphs: [Morph(吾輩), Morph(は)] ),
Chunk( id: 1, dst: 2, srcs: [], morphs: [Morph(ここ), Morph(で)] ),
Chunk( id: 2, dst: 3, srcs: ['1'], morphs: [Morph(始め), Morph(て)] ),
Chunk( id: 3, dst: 4, srcs: ['2'], morphs: [Morph(人間), Morph(という)] ),
Chunk( id: 4, dst: 5, srcs: ['3'], morphs: [Morph(もの), Morph(を)] ),
Chunk( id: 5, dst: -1, srcs: ['0', '4'], morphs: [Morph(見), Morph(た), Morph(。)] )]
Returns:
List[Tuple[str, str]]: Edges.
e.g. [('ここで', '始めて'),
('始めて', '人間という'),
('人間という', 'ものを'),
('吾輩は', '見た'),
('ものを', '見た')]
"""
edges = []
for chunk in chunks:
if len(chunk.srcs) == 0:
continue
post_node = chunk.get_surface()
for src in chunk.srcs:
src_chunk = chunks[int(src)]
pre_node = src_chunk.get_surface()
edges.append((pre_node, post_node))
return edges
def draw_graph(edges):
graph = pydot.Dot(graph_type="digraph")
for edge in edges:
graph.add_edge(pydot.Edge(edge[0], edge[1]))
graph.write_png("demo_graph.png")
fpath = "neko.txt.cabocha"
sentences = read_file(fpath)
sentences = [convert_sent_to_chunks(sent) for sent in sentences] # ans41
# ans44
edges = get_edges(sentences[5]) # May return empty list
draw_graph(edges)
# edges:
# [('ここで', '始めて'),
# ('始めて', '人間という'),
# ('人間という', 'ものを'),
# ('吾輩は', '見た'),
# ('ものを', '見た')]
