Trees

[Tim Chase]

On 2015-01-21 23:35, Chris Angelico wrote:
> On Wed, Jan 21, 2015 at 11:09 PM, Rustom Mody wrote
> > Its a bit of a nuisance that we have to write set([1,2,3]) for
> > the first
> 
> Wait, what?
> 
> rosuav at sikorsky:~$ python
> Python 2.7.3 (default, Mar 13 2014, 11:03:55)
> [GCC 4.7.2] on linux2
> Type "help", "copyright", "credits" or "license" for more
> information.
> >>> type({1,2,3})
> <type 'set'>
> >>>
> rosuav at sikorsky:~$ python3
> Python 3.5.0a0 (default:4709290253e3, Jan 20 2015, 21:48:07)
> [GCC 4.7.2] on linux
> Type "help", "copyright", "credits" or "license" for more
> information.
> >>> type({1,2,3})
> <class 'set'>
> >>>
> 
> Looks like {1,2,3} works for me.

That hasn't always worked:

tim at bigbox:~$ python2.5
Python 2.5.5 (r255:77872, Nov 28 2010, 16:43:48) 
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> type({1,2,3})
  File "<stdin>", line 1
    type({1,2,3})
           ^
SyntaxError: invalid syntax

tim at bigbox:~$ python2.6
Python 2.6.8 (unknown, Jan 26 2013, 14:35:25) 
[GCC 4.7.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> type({1,2,3})
  File "<stdin>", line 1
    type({1,2,3})
           ^
SyntaxError: invalid syntax

And, prior to 2.4, you had to write

  from sets import Set as set

to even get sets.

  https://docs.python.org/2/whatsnew/2.4.html#pep-218-built-in-set-objects

-tkc