""" some helper functions """

import openpyxl


def get_sheet_of_file(excel_file, name=None):
    """ returns a sheet from an excel FileCache

    if name is set to None, the function returns the first sheet
    """
    workbook = openpyxl.open(excel_file)
    if name is None:
        sheets = workbook.sheetnames
        name = sheets[0]
    return workbook[name]