def color_scale_columns(df,matplotlib_cmap = "Greens",subset=None,):
    """
    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.
    Ex. color_scale_columns(df,"YlGn")
    
    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
    Colormap to use instead of default seaborn green.  
    
    Returns:
    ----------
    df_style : df.style

    """ 
    cm = matplotlib_cmap
    #     cm = sns.light_palette("green", as_cmap=True)
    df_style = df.style.background_gradient(cmap=cm,subset=subset)#,low=results.min(),high=results.max())
    # Display styled dataframe
#     display(df_style)
    return df_style