I found some useful code(Even, it is not efficient way to handle the logs files)
#!/bin/bash
MaxFileSize=10000000
#Max file size 10MB
while true
do
python /root/rtt/rtt.py >> /root/script_logs/rtt.log
sleep 60
com=`du -b /root/script_logs/rtt.log`
file_size=`echo $com | cut -d' ' -f1`
if [[ "$file_size" -gt "$MaxFileSize" ]]
then
echo ' ' > /root/script_logs/rtt.log
fi
done