[Tutor] use of the newer dict types

[Albert-Jan Roskam]

----- Original Message -----

> From: Alan Gauld <alan.gauld at btinternet.com>
> To: tutor at python.org
> Cc: 
> Sent: Friday, July 26, 2013 1:12 PM
> Subject: Re: [Tutor] use of the newer dict types
> 
> On 26/07/13 09:50, Albert-Jan Roskam wrote:
> 
>>  if I have d = {1: 2}, I can do membership testing in the following
>>  two ways --but which one is the preferred way?:
>>  if 1 in d:
>>       pass
>>  if d.has_key(1):
>>        pass
> 
> 
> In addition to being more readable (and the fact it's the only way in 
> v3) 'in' has another big advantage - it's polymorphic:
> 
> holds_1 = []
> bigBox = [ {1:2,3:4}, ['a',2,;freddy',True], (1,2,3)  ]
> 
> for collection in bigBox:
>     if 1 in collection:
>        holds_1.append(collection)
> 
> You can't do that using has_key(), the code has to test
> for dict type etc.
> 
> So all in all 'in' is the way to go.

Hmm, I'm in (pun intended ;-). Those are three very good arguments. I'll have a look if my IDE (PyCharm) warns about the incompatibility with Python 3.x (t does so with several things, like u'). Thank you!