def color_scale_columns(df, matplotlib_cmap='Greens', subset=None):
    """DataFrame Styler:
    Takes a df, any valid matplotlib colormap column names
    (matplotlib.org/tutorials/colors/colormaps.html) and
    returns a dataframe with a gradient colormap applied to column values.

    Example:
    df_styled = color_scale_columns(df,cmap = "YlGn",subset=['Columns','to','color'])

    Parameters:
    -----------
        df:
            DataFrame containing columns to style.
    subset:
         Names of columns to color-code.
    cmap:
        Any matplotlib colormap.
        https://matplotlib.org/tutorials/colors/colormaps.html

    Returns:
    ----------
        df_style:
            styled dataframe.

    """
    from IPython.display import display
    import seaborn as sns
    cm = matplotlib_cmap
    df_style = df.style.background_gradient(cmap=cm, subset=subset)
    return df_style
