[Edu-sig] The fate of raw_input() in Python 3000

[Dethe Elza]

On 4-Sep-06, at 5:45 PM, Andre Roberge wrote:

> The following is something I have been pondering for quite a while now
> and am wondering what other people on this list think.
>
> According to PEP 3100
> (http://www.python.org/dev/peps/pep-3100/ )
> raw_input()  [as well as input()] is recommended for removal from the
> built-in namespace, to be replaced by sys.stdin.readline().

But it is trivial to add this back in:

 >>> raw_input = sys.stdin.readline

> While I don't think anyone can argue that this removal makes a major
> difference for Python as a programming language, I believe it makes a
> significant difference for using Python as a learning language, adding
> a non-trivial barrier to learning.

Removing this from built-ins isn't going to be any more confusing or  
off-putting than trying to understand the difference between input  
and raw_input in the first place.  I remember being tripped up by  
*that* when I was first learning Python.


> Consider the following fake sessions at the interpreter prompt, where
> I use extra parentheses to turn print as a function (as is also
> proposed in Python 3000) - these parentheses can of course be used
> with today's Python.

The standard prompt is great, but not the best learning environment.   
I would recommend that students use IPython instead, and since  
IPython already adds lots of convenience methods to the global  
namespace, there's nothing to stop it from pre-populating globals  
with input and raw_input.

That is:

1. It isn't necessary for global functions at the command-line prompt  
to be in builtins
2. It possible (and desirable) to have different command-line prompts  
for different purposes
3. It isn't necessary to clutter the builtins with every convenience  
function, even if we're used to it

Now, all that given, I do hope Python doesn't start going down the  
road that Java has taken and replace

 >>> open('myfilename.txt')

with

 >>> open(BufferedStream(InputStream(FileStream('myfilename.txt')

but I don't think the loss of raw_input is quite on that scale.

--Dethe

Art is either plagiarism or revolution. --Paul Gauguin