Use property for attribute access
Use property for attribute access

Cleaned up the code and now using property for attribute access.

BruceSherwood/vpython-jupyter,BruceSherwood/vpython-jupyter,mwcraig/vpython-jupyter,BruceSherwood/vpython-jupyter,sspickle/vpython-jupyter,mwcraig/vpython-jupyter,BruceSherwood/vpython-jupyter,mwcraig/vpython-jupyter,mwcraig/vpython-jupyter,sspickle/vpython-jupyter