Regex based Python function to count the number of sentences in a given string.

count_sentences.py

import re


def count_sentences(text: str) -> int:
    """
    Count the number of sentences in a given string.
    This function is based on the Stack Overflow answer https://stackoverflow.com/a/38589115/7706917

    Inputs
    --------
    text : str

    Returns
    --------
    int
        The number of sentences in the given string.
    """
    exp = r"[!?]+|(?<!\.)\.(?!(?<=\d.)\d)(?!\.)"
    sentences = re.split(exp, text.replace("\n", ""))
    sentences = sentences[:-1]
    return len(sentences)