Python list copy, Python tuple copy

Full-slicing a list builds a new list:

  >>> old = [1, 2, 3]
  >>> new = old[:]
  >>> old is new       
  False

But full-slicing a tuple does NOT build a new tuple:

  >>> old = (1, 2, 3)
  >>> new = old[:]
  >>> old is new
  True

Python tuple unpacking within a loop

Python tuple unpacking gets rid of tuple indices and temporary variables.

   >>> a = range(11, 15)
   >>> b = zip(range(21, 25), range(31, 35))
   >>> for x, (y, z) in zip(a, b):
   ...     print x, y, z
   ... 
   11 21 31
   12 22 32
   13 23 33
   14 24 34

Definitional tuple-packing in Python

Python functions may tuple-pack their arguments.

   def foo(a, (b, c)):
      print a, b, c

   >>> foo(10, (20, 30))
   10 20 30

Arguments unpack during evaluation.