why my python app exist immediately after show graph diagram? : I use below code to show a data graph but the graph window is just shown for one second then the application exists. Below is my code. Is there anything wrong with it?

    import seaborn as sns
    import pandas as pd
    import matplotlib.pyplot as plt
    
    train_df = pd.read_csv('./data/tra

in.csv')

    g = sns.FacetGrid(train_df, col='Survived')
    g.map(plt.hist, 'Age', bins=20)