clean_funcs.py

import re
import unicodedata
from functools import reduce
from itertools import groupby
from string import punctuation

url_regex = re.compile(r"((www\.[^\s]+)|(https?://[^\s]+)|(http?://[^\s]+))")
control_char_regex = re.compile(r"[\r\n\t]+")
phone_number_regex = re.compile("\(?\+?\d[\s\d()-]{5,}\d")
finnish_social_id_regex = re.compile("\d{6}[-+Aa]\d{3}[a-zA-Z0-9]")
email_regex = re.compile(r"[\w.+-]+@[\w-]+\.[\w.-]+")


def clean_text(example) -> str:
    data_preprocessing_funcs = [
        _replace_identity,
        _replace_phone_number,
        _replace_url,
        _replace_email,
        _fix_html,
        _standardise_punc,
        _remove_unicode_symbols,
        _remove_control_char,
        _remove_remaining_control_chars,
        _remove_multiple_punctuation,
        _remove_multi_space,
    ]
    return reduce(lambda x, y: y(x["text"]), data_preprocessing_funcs, example)


def _standardise_punc(text: str) -> str:
    transl_table = dict([(ord(x), ord(y)) for x, y in zip("‘’´“”–-", "'''\"\"--")])
    text_mod = text.translate(transl_table)
    text_mod = re.sub(r"[^a-zA-Z0-9À-ÿ .,'%&€$=@+;<>/()!?%:-]", " ", text_mod)
    return {"text": text_mod}


def _remove_control_char(text: str) -> str:
    text_mod = re.sub(control_char_regex, " ", text)
    return {"text": text_mod}


def _remove_remaining_control_chars(text: str) -> str:
    text_mod = "".join(ch for ch in text if unicodedata.category(ch)[0] != "C")
    return {"text": text_mod}


def _remove_multi_space(text: str) -> str:
    text_mod = " ".join([txt for txt in text.split(" ") if txt and txt != ""])
    return {"text": text_mod}


def _remove_unicode_symbols(text: str) -> str:
    text_mod = "".join(ch for ch in text if unicodedata.category(ch)[0:2] != "So")
    return {"text": text_mod}


def _replace_url(text: str) -> str:
    filler = ""
    occ = text.count("www.") + text.count("http:") + text.count("https:")
    text_mod = text
    for _ in range(occ):
        # replace other urls by filler
        text_mod = re.sub(url_regex, filler, text_mod)
        text_mod = " ".join(text_mod.split())
    return {"text": text_mod}


def _fix_html(text: str) -> str:
    text_mod = (
        text.replace("#39;", "'")
        .replace("amp;", "&")
        .replace("#146;", "'")
        .replace("nbsp;", " ")
        .replace("\\n", "\n")
        .replace("quot;", "'")
        .replace("<br />", "\n")
        .replace('\\"', '"')
        .replace(" @.@ ", ".")
        .replace(" @-@ ", "-")
        .replace("...", " …")
    )
    return {"text": text_mod}


def _replace_phone_number(text: str) -> str:
    text_mod = re.sub(phone_number_regex, " ", text)
    return {"text": text_mod}


def _replace_identity(text: str) -> str:
    text_mod = re.sub(finnish_social_id_regex, " ", text)
    return {"text": text_mod}


def _replace_email(text: str) -> str:
    text_mod = re.sub(email_regex, " ", text)
    return {"text": text_mod}


def _remove_news_tags(text: str) -> str:
    text_mod = re.sub(r"(<[A-Z].+?>)|(</[A-Z].+?>)", " ", text)
    return {"text": text_mod}


def _remove_multiple_punctuation(text: str) -> str:
    text_mod = re.sub(r"\b(\w+)( \1\b)+", r"\1", text)
    punc = set(punctuation)
    newtext = []
    for k, g in groupby(text_mod):
        if k in punc:
            newtext.append(k)
        else:
            newtext.extend(g)
    text_mod = "".join(newtext)
    return {"text": text_mod}