How to get output of all directery file error with single topy .py

$ ./topy.py `find /home/sanu/horizon -type f -name "*.py" -exec echo {} \;`

$ find /home/sanu/horizon -type f -name "*.py" -exec echo {} \;

$ cat 'find /home/sanu/horizon -type f -name "*.py" -exec echo {} \;'