Make Python3 default without breaking yum in RHEL7

> **What specific syntax needs to be changed or added to the below in order for commands calling python in a RHEL7 VM to be interpreted using Python3 WITHOUT breaking programs like yum that require Python2?** **FIRST ATTEMPT:** Our first attempt was to add the following 2 lines to the very end of the cloud-init startup script which instantiates the VM: rm /usr/bin/python ln -s /usr/bin/python3 /usr/bin/python **ERROR THAT RESULTED:** The problem is that adding the above two lines to the end of the cloud-init startup script causes yum commands to break when yum is called afterwards as follows: $ sudo yum update -y File "/bin/yum", line 30 except KeyboardInterrupt, e: ^ SyntaxError: invalid syntax $ **TOGGLING THE ERROR:** We can turn off the error by removing the above 2 lines from the cloud-init startup script and re-instantiating a new replacement VM. This isolates the source of the problem, but still we have the problem of how to default python to Python3 without breaking apps like yum.