Thanks Damanvir!  Changing the line in /usr/bin/yum worked!
This is a little off topic and might be removed but it might help someone.  
These are the steps I used to install Python 3.7 on Centos and fix the yum error.
Download from https://www.python.org/
tar -xvf
./configure --enable-optimizations
make
make install
OR 
make altinstall
make altinstall is used to prevent replacing the default python binary file /usr/bin/python.
cd /usr/bin
Remove the current symbolic link to the previous version
rm python
OUTPUT:   rm: remove symbolic link ‘python’? y
Find the location of the new version
whereis python3.7
 OUTPUT: python3: /usr/local/bin/python3.7
Verify this is correct
  /usr/local/bin/python3.7 --version
  OUTPUT: Python 3.7.0
Create a symbolic link to the location of the new version
ln -s /usr/local/bin/python3.7 python
python --version
OUTPUT:  Python 3.7.0
Yum commands will show the following error:
  File "/bin/yum", line 30
      except KeyboardInterrupt, e:
  SyntaxError: invalid syntax
Change the top line of this file from using python to python2
  vi /usr/bin/yum 
    #!/usr/bin/python2
Reference: https://tecadmin.net/install-python-3-7-on-centos/