def _get_number_of_column_label(label):
    """
    This function returns a number which corresponds to the label.
    Example : 'A' -> 1 , 'Z' -> 26 , 'AA' -> 27 , 'BA' -> 53

    Args : 
        label : Type-str
            Denotes the label given to the column by sheets
    Returns :
        num : Type-int
            Denotes the numbering of columns(1-indexed)

    """

    num = 0
    power_of_26 = 1

    for i in range(len(label)-1,-1,-1):
        value = ord(label[i]) - ord('A') + 1

        num += power_of_26*value

        power_of_26 = 26*power_of_26

    return num