Coreference resolution using coreferee and spacy

resolve_coreference.py

import spacy
import coreferee

def flatten(list_of_lists):
    flat_list = [];
    for item in list_of_lists:
        if type(item) == list:
            for sub_item in item:
                flat_list.append(sub_item)
        else:
            flat_list.append(item)
    return flat_list

def non_empty(replacement):
    return replacement[1] != None if 1 < len(replacement) else False

def to_string_replacement(replacement):
    [i, tokens] = replacement
    return [i, str(tokens)]

def replacements(doc):
    def resolve(mention):
        return flatten(list(
            map(to_string_replacement,
                filter(non_empty,
                    map(lambda i: [i, doc._.coref_chains.resolve(doc[i])],
                            mention)))))
    def to_replacements(chain):
        return list(filter(non_empty, map(resolve, chain)))
    return flatten(list(map(to_replacements, doc._.coref_chains)))

def resolved_text(doc):
    tokens = list(token.text for token in doc)
    for [i, replacement] in replacements(doc):
        tokens[i] = replacement
    return " ".join(tokens)

def resolve_coreference(text):
    nlp = spacy.load('en_core_web_trf')
    nlp.add_pipe('coreferee')
    return resolved_text(nlp(text))

resolve_coreference('Akiva Eldar is the chief political columnist and ' +
'an editorial writer for Haaretz. His columns also appear regularly in the ' +
'Ha\'aretz-Herald Tribune edition. In May 2006, The Financial Times selected ' +
'him among the most prominent and influential commentators in the world, and ' +
'his comments inspire callers from across the political spectrum')
# Akiva Eldar is the chief political columnist and an editorial writer for
# Haaretz . [Eldar] columns also appear regularly in the Ha’aretz - Herald
# Tribune edition . In May 2006 , The Financial Times selected [Eldar] among the
# most prominent and influential commentators in the world , and [Eldar]
# comments inspire callers from across the political spectrum