On Sat, Jul 13, 2019 at 09:59:16AM +1000, Cameron Simpson wrote: > Mike has probably confused this with tuples. Because tuples are > delineated with parentheses, there is ambiguity between a tuple's > parentheses and normal "group these terms together" parentheses.
There are no "tuple parentheses". Tuples are created by the *comma*, not the parens. The only exception is the empty tuple, since you can't have a comma on its own. x = () # Zero item tuple. x = 1, # Single item tuple. x = 1, 2 # Two item tuple. Any time you have a tuple, you only need to put parens around it to dismbiguate it from the surrounding syntax: x = 1, 2, (3, 4, 5), 6 # Tuple containing a tuple. function(0, 1, (2, 3), 4) # Tuple as argument to a function. or just to make it more clear to the human reader. > Here is a 2 element tuple: > > (9, 7) > > How does one write a one element tuple? Like this: > > (9,) To be clear, in both cases you could drop the parentheses and still get a tuple: 9, 7 9, provided that wasn't in a context where the comma was interpreted as something with higher syntactic precedence, such as a function call: func(9, 7) # Two integer arguments, not one tuple argument. func((9, 7)) # One tuple argument. -- Steven _______________________________________________ Tutor maillist - Tutor@python.org To unsubscribe or change subscription options: https://mail.python.org/mailman/listinfo/tutor