standard python ( cpythononly' alternative implementations such as jythonironpythonand pypy may use different schemesthough the net effect in all is similar--unused space is reclaimed for you automaticallyif not always as immediately shared references so farwe've seen what happens as single variable is assigned references to objects now let' introduce another variable into our interaction and watch what happens to its names and objectsa typing these two statements generates the scene captured in figure - the second command causes python to create the variable bthe variable is being used and not assigned hereso it is replaced with the object it references ( )and is made to reference that object the net effect is that the variables and wind up referencing the same object (that ispointing to the same chunk of memoryfigure - names and objects after next running the assignment variable becomes reference to the object internallythe variable is really pointer to the object' memory space created by running the literal expression this scenario in python--with multiple names referencing the same object--is usually called shared reference (and sometimes just shared objectnote that the names and are not linked to each other directly when this happensin factthere is no way to ever link variable to another variable in python ratherboth variables point to the same object via their references nextsuppose we extend the session with one more statementa 'spamas with all python assignmentsthis statement simply makes new object to represent the string value 'spamand sets to reference this new object it does nothowever the dynamic typing interlude