def sent_pie_chart(plt, sent, text_fontsize = 15):
    """
    This function creates a matplotlib pie chart
    
    Arguments
        plt  : matplotlib.pyplot plot
        sent : pandas dataframe column with
               "Positive", "Negative" or "Neutral"
    
    Returns
        updated plt object
    """
    
    # Code to set custom colors inspired by this
    # https://stackoverflow.com/questions/35206282/assign-specific-colours-to-data-in-matplotlib-pie-chart
    
    labels = [s for s in sent.value_counts().index]
    
    colors = {"Positive": "greenyellow",
              "Neutral": "skyblue",
              "Negative": "crimson"}
    
    plt.pie(sent.value_counts(), 
            labels = labels,
            autopct = '%.0f%%',
            pctdistance = 0.7,
            startangle = 90,
            textprops = {'fontsize': text_fontsize},
            colors = [colors[sent] for sent in labels])
      
    return plt