I made the default value of a parameter in a function definition a function call. I find in practice that this only gets evaluated the first time the function is called, so ended up defaulting to None with a test and call in the code.
This results in time.time() only being called once, with all subsequent calls picking up the value from the first call. Clearly not what I was expecting!def nicetimeinterval(timethen, timenow=time.time())
diff = int(timenow-timethen
This is with Python 3