Hamilton, William <[EMAIL PROTECTED]> wrote:
>> From: Beliavsky
> On May 15, 1:30 am, Anthony Irwin <[EMAIL PROTECTED]> wrote:
>> <snip>
>>> #5 someone said that they used to use python but stopped because the
>>> language changed or made stuff depreciated (I can fully remember
>>> which) and old code stopped working. Is code written today likely to
>>> still work in 5+ years or do they depreciate stuff and you have to
>> update?
The word is "deprecated." ("Depreciated" would be a financial term,
not a term of art in computer science).
>> Because Python 3 will change the syntax of print to disallow
>> print "Hello, world."
Python 3 is an exception case because it's the only time that the
BFDL has specifically and intentionally declared that backward
compability was NOT a goal for that version.
Essentially you can consider Python 3 to be a fork ... a departure
from Python 2.x and earlier.
This specific change, for example, is intended to remove a
consistency wart in the language. The "print" statement in Python
is a special case. It's not a normal built-in function and it's not
an expression.
You can start writing all your code now as: print() --- calling
the statement as if it were a function. Then you're future Python
3 work would consist of simply defining a suitable function named
print() (if one isn't provided or the one provided isn't suited
to your needs).
>> a substantial fraction of Python programs in existence, including all
>> of my programs, will be broken. Draw your own conclusions.
Python 3 will be a different language. It'll be similar, perhaps
to the disruption between Perl 4 and Perl 5; or between Perl 5 and
the proposed changes to Perl 6.
Keep in mind that Java has had a number of features deprecated
as well. The disruption from Java 1.x to Java2 and thence to Java5
is probably greater than the level of disruption between Python 1.x
and Python 2.5.x (which as been a roughly equivalent length of time
--- over a decade in both cases).
> No, they'll work just fine. They just won't work with Python 3. It's not
> like the Python Liberation Front is going to hack into your computer in the
> middle of the night and delete you 2.x installation.
> ---
> -Bill Hamilton
Yes, considering this to be more like a fork then an upgrade is the
wise approach. Many Linux distributions, for example, will probably
ship and concurrently install Python 2.x and Python 3.x for a several
years after Python 3 ships.
--
Jim Dennis,
Starshine: Signed, Sealed, Delivered
--
http://mail.python.org/mailman/listinfo/python-list
