@staticmethod
def _excel_string_width(string):
    """
        Calculate the rough length of a string in Excel character units.
        This is highly inaccurate and doesn't account for font size etc.
        
        Parameters
        ----------
        string : str
            string to calculate width in Excel for
        
        Returns 
        -------
        string_width : float
            width of equivalent string in Excel
        """
    string_len = len(string)
    if string_len == 0:
        excel_width = 0
    else:
        excel_width = string_len * 1.1
    return excel_width
