Actually, no, shortening names won't speed bytecode up in the way you seem to be suggesting. Variables "are" indexed by position in some arrays like co_varnames

Actually, no, shortening names won't speed bytecode up in the way you seem to be suggesting. Variables "are" indexed by position in some arrays like co_varnames, co_names, co_const and so on. See for example https://docs.python.org/3.8/library/dis.html?highlight=co_names#opcode-LOAD_FAST https://docs.python.org/3.8/library/dis.html?highlight=co_na... There are maps in the code object that will turn the index back into a name, but that's only used when some sort of introspection occurs, such as you might find in a debugger or traceback. The names found in an "import" of course is a string so there might some small advantage there in a shorter name.