将nltk树转换为JSON表示

Posted 2021-04-25

我想将以下nltk树表示转换为JSON格式：

期望的输出：

{
    "scores": {
        "filler": [
            [
                "scores"
            ],
            [
                "for"
            ]
        ],
        "extent": [
            "highest"
        ],
        "team": [
            "India"
        ]
    }
}

答案

看起来输入树可能包含具有相同名称的子项。为了支持一般情况，您可以将每个Tree转换为将其名称映射到其子列表的字典：

from nltk import Tree # $ pip install nltk

def tree2dict(tree):
    return {tree.node: [tree2dict(t)  if isinstance(t, Tree) else t
                        for t in tree]}

例：

import json
import sys

tree = Tree('scores',
            [Tree('extent', ['highest']),
             Tree('filler',
                  [Tree('filler', ['scores']),
                   Tree('filler', ['for'])]),
             Tree('team', ['India'])])
d = tree2dict(tree)
json.dump(d, sys.stdout, indent=2)

输出：

{
  "scores": [
    {
      "extent": [
        "highest"
      ]
    }, 
    {
      "filler": [
        {
          "filler": [
            "scores"
          ]
        }, 
        {
          "filler": [
            "for"
          ]
        }
      ]
    }, 
    {
      "team": [
        "India"
      ]
    }
  ]
}

另一答案

将Tree转换为dict，然后转换为JSON。

def tree_to_dict(tree):
    tdict = {}
    for t in tree:
        if isinstance(t, nltk.Tree) and isinstance(t[0], nltk.Tree):
            tdict[t.node] = tree_to_dict(t)
        elif isinstance(t, nltk.Tree):
            tdict[t.node] = t[0]
    return tdict

def dict_to_json(dict):
    return json.dumps(dict)

output_json = dict_to_json({tree.node: tree_to_dict(tree)})

另一答案

将树转换为以树标签为键的字典，然后您可以使用JSON转储将其转换为JSON

    import nltk.tree.Tree

    def tree_to_dict(tree):
        tree_dict = dict()
        leaves = []
        for subtree in tree:
            if type(subtree) == nltk.tree.Tree:
                tree_dict.update(tree_to_dict(subtree))
            else:
                (expression,tag) = subtree
                leaves.append(expression)
        tree_dict[tree.label()] = " ".join(leaves)

        return tree_dict

另一答案

相关的替代方案。出于我的目的，我不需要保留精确的树，而是想要将实体作为键和标记提取为值列表。对于“汤姆和拉里为爱国者队效力”这句话。我想要以下JSON：

{
  "PERSON": [
    "Tom",
    "Larry"
  ],
  "ORGANIZATION": [
    "Patriots"
  ]
}

这保留了令牌的顺序（每个实体类型），同时也没有为实体键设置的“stomping”值。您可以在其他答案中重复使用相同的json.dump代码将此dict返回给json。

from nltk import tag,chunk,tokenize

def prep(sentence):
    return chunk.ne_chunk(tag.pos_tag(tokenize.word_tokenize(sentence)))

t = prep("Tom and Larry play for the Patriots.")

def tree_to_dict(tree):
    tree_dict = dict()
    for st in tree:
        # not everything gets a NE tag,
        # so we can ignore untagged tokens
        # which are stored in tuples
        if isinstance(st, nltk.Tree):
            if st.label() in tree_dict:
                tree_dict[st.label()] = tree_dict[st.label()] + [st[0][0]]
            else:
                tree_dict[st.label()] = [st[0][0]]
    return tree_dict

print(tree_to_dict(t))
# {'PERSON': ['Tom', 'Larry'], 'ORGANIZATION': ['Patriots']}