So with a Singleton what you can do at least in Java land is have your service invoke the method to get the Singleton semi-global object.

So you can mock that method invocation to return a different object. So you basically have the local object to play with in your test and won't be affecting any actual real global state

But basically the article was just saying just use global variables. Does python have a means for then intercepting the value request and data assignments for that global variable for the local scope of the testing code? Or is it hardwired like a global variable, presumably is?