<s>[INST] What is an alternative to execfile in Python 3.0? It seems they canceled in Python 3.0 all the easy way to quickly load a script file - both execfile() and reload(). 
Is there an obvious alternative I'm missing?
 [/INST] You are just supposed to read the file and exec the code yourself. 2to3 current replaces
execfile("somefile.py", global_vars, local_vars)

as
with open("somefile.py") as f:
    code = compile(f.read(), "somefile.py", 'exec')
    exec(code, global_vars, local_vars)

(The compile call isn't strictly needed, but it associates the filename with the code object making debugging a little easier.)
See:

http://docs.python.org/release/2.7.3/library/functions.html#execfile
http://docs.python.org/release/3.2.3/library/functions.html#compile
http://docs.python.org/release/3.2.3/library/functions.html#exec

 </s>