Update app.py

app.py

@@ -6,6 +6,7 @@ from gensim.models.doc2vec import Doc2Vec, TaggedDocument
 from nltk.tokenize import word_tokenize
 import PyPDF2
 import pandas as pd
+from numpy.linalg import matrix_upper_triangular as triu
 import re
 import matplotlib.pyplot as plt
 import seaborn as sns