In previous chapters we've already talked about and used "variables" in Python, but what exactly is a variable? Consider something as straightforward as assigning an integer to a variable:
>>> x = 1000
What's really happening when we do this? First, Python creates an int object with a value of 1000. This object is anonymous in the sense that it doesn't, in and of itself, have a name (x or otherwise). It's simply an object allocated and tracked by the Python runtime system.
After creating the object, Python then creates an object reference with the name x and arranges for x to refer to the int(1000) object:
Figure 4.1: Assign the name 'x' to an integer object with the value 1000