changed matplotlib to use agg backend

app.py

@@ -3,6 +3,7 @@ import re
 import sys
 import nltk
 import praw
+import matplotlib
 import gradio as gr
 import pandas as pd
 import praw.exceptions
@@ -10,6 +11,8 @@ import matplotlib.pyplot as plt
 from wordcloud import WordCloud
 from transformers import pipeline
 
+matplotlib.use('Agg')
+
 
 def index_chunk(a):
     n = round(0.3 * len(a))