[Tutor] multiple objects with one assignment?

Dave Angel davea at davea.name
Fri Jan 2 12:27:15 CET 2015

On 01/02/2015 05:25 AM, Brandon Dorsey wrote:
> I know there is are easier ways to assign multiple objects to a variable,
> but why, does the following code work?  Why does it return a tuple versus a
> list?  I know it has something to do with the semi-colon, but I didn't know
> it wouldn't  raise an error.
> greetings = "hello,", "what's", "your", "name?"
> print(greetings)
> x = 1, 2, 3, 4, 5, 6, 7
> print(x)
> I assumed that you could only assign one object per assignment without the
> presence of tuples, list, or dictionaries.

Ben's description is very good.  But I think the main thing you're 
missing is that a tuple is created by the comma, not by parentheses.  In 
some contexts, parentheses need to be added to make it non-ambiguous, 
since comma is overloaded.

a = 1, 2, 3

1,2,3 is a tuple.  This statement is identical to:

a = (1, 2, 3)

Likewise when you say:

return 1, 2

you are returning a tuple.

If you are passing a (literal) tuple as an argument to a function, you 
would need parens, since the function call also uses commas to separate 
the arguments:

myfunc(val1, (21, 22, 23), val3)

Here the function is being called with 3 arguments:
    the tuple


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