def normalise_column(df, column):
    """
    Normalise a column of floats

    :param df: data frame
    :param column: column name
    :return: data frame with update column
    """

    max_c = df[column].max()
    min_c = df[column].min()

    if max_c == min_c:
        df[column] = df[column].apply(lambda x: 0)
    else:
        df[column] = df[column].apply(lambda x: float(
            (x - min_c)) / float((max_c - min_c)))

    return df