import re


def clean_columns(column_list):
    """
    Little helper to clean up column names quickly.
    :param column_list: List of column names.
    :return: List of cleaned up column names.
    """
    def _scrub_col(column):
        no_spc_char = re.sub(r'[^a-zA-Z0-9_\s]', '', column)
        no_spaces = re.sub(r'\s', '_', no_spc_char)
        return re.sub(r'_+', '_', no_spaces)
    return [_scrub_col(col) for col in column_list]