[Python] What kind of object is this?

[navneeth]

What I first thought was a typo in the book Beginning Python, 2 ed., by Magnus Lie Hetland, turned out to be a valid assignment.

In showing how to use the join() function, the author defines the following object:


dirs = '','usr','bin','env'

What is this? On first reading, I assumed it was a list (or a queue, perhaps) missing the brackets, but when I tried it in the interpreter, Python didn't seem to mind.

[Zugzwang]

That is a "tuple": http://docs.python.org/tutorial/datastructures.html#tuples-and-sequences

[capybara!]

It's a python built in 'tuple' object. You can get the type with the 'type()' function:



type(dirs)
<type 'tuple'>


Type 'help tuple' into your python shell and you'll see what you can do with the tuple object...

[navneeth]

Oh. Now that I turn back the pages, I see that he mentions that you can create a tuple simply by separating the entries by commas.:oops: I have been used it as something enclosed within (). (Oh, and did I say "queue"? What's wrong with me! I actually meant tuple there.)

Thanks, guys.

[navneeth]

It's a python built in 'tuple' object. You can get the type with the 'type()' function:



type(dirs)
<type 'tuple'>




Never heard of that function before, but I'm sure it will come in handy in future. Thanks once again. :)

[Can+~]

Never heard of that function before, but I'm sure it will come in handy in future. Thanks once again. :)

Those are called the built-in functions (http://docs.python.org/library/functions.html). It's always good to know this general-purpose function, I remember when I swapped an entire piece of code with a single "cmp" function.

Also, try to prefer the "(a, b, c)" notation for tuples, it's more explicit.