Issue with finding average in python

Question

import sqlite3
import csv

conn=sqlite3.connect("D:/asdfef.xdb")

cur=conn.cursor()

cur.execute("select max(ue_rsrp) from  lte_ue_rf") #sql query to calculate the avergae

rows = cur.fetchall() 

columns = [i[0] for i in cur.description]

with open("D:/asdf.csv",'w') as file:
   writer=csv.writer(file)
   writer.writerow(columns)
   writer.writerow(rows)

Above is the code used to retrieve the avg of an item in the DB, but my output shows up as a list (-79.25,). Why is this happening and what should be done to rectify this. I am a beginner with python coding