import re


def read_data_table(filename: "str") -> "dict":
    """
    Reads in a CSV file containing columnwise data for various elements, and returns a dictionary containing the data.
    Lines beginning with "#" are ignored
    :param filename: A valid filename for a csv file
    :type filename: str

    :return: A dictionary containing the data of interest
    """
    values = {}
    with open(filename, "r") as data:
        for line in data:
            if re.match("^(\s+#|#|\s+$)", line):
                continue
            elif re.match("^(\s|\s+)$", line):
                continue
            key, value = line.strip().split(",")
            values[key] = float(value)

    return values