currency_cleaner.py

import re

CURRENCY_LIST = {"£": "pounds", "$": "dollars", "€": "euros"}

CURRENCY_PATTERN = fr"((?:[{''.join(CURRENCY_LIST.keys())}]+\d*)(?:\,*\d+)(?:\.\d+)?(?i:[km])*)|(\d+(?:\,*\d+)(?:\.\d+)?(?i:[km])*(?:[{''.join(CURRENCY_LIST.keys())}]+))|((?:[{''.join(CURRENCY_LIST.keys())}]+))"

def _currency_to_text(text: str) -> str:
    clean = (
        lambda x: x.lower()
        .replace(",", "")
        .replace("k", " thousand")
        .replace("m", " million")
        .replace("mn", " million")
        .replace("b", " billion")
        .replace("bn", " billion")
    )

    currency_matcher = re.compile(CURRENCY_PATTERN)
    f = lambda x: list(filter(None, x))[0]
    matches = []

    for m in currency_matcher.findall(text):
        matches.append(f(m))

    if matches:
        for m in matches:
            if m[0] in CURRENCY_LIST:
                idx = 0
                while (idx < len(m)) and (m[idx] in CURRENCY_LIST):
                    idx += 1
                text = text.replace(m, f"{clean(m[idx:])} {CURRENCY_LIST[m[0]]}")
                continue

            idx = 0
            while (idx < len(m)) and (m[idx] not in CURRENCY_LIST):
                idx += 1
            text = text.replace(m, f"{clean(m[:idx])} {CURRENCY_LIST[m[idx]]}")
    return text


if '__name__' == '__main__':
  sentences = [
    "and the super cheap add on of great muffins too! large + muffin $2.50, that's awesome!",
    "You wouldn't worry so much if you had $1B, you know?"
    "How about you pay 25k$ for it?",
    "My tuition was $100,000.50. I paid through my nose."
  ]
  for sent in sentences:
    print(_currency_to_text(sent))