* Daniel Fetchinson:
* Print is now a function. Great, much improvement.
Actually not, IMHO. All it does is is to provide incompatibility.
What incompatibility are you exactly talking about?
Python 2.6.2 (r262:71600, Aug 21 2009, 12:23:57)
[GCC 4.4.1 20090818 (Red Hat 4.4.1-6)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
print( 'hello' )
hello
print 'hello'
hello
Yes, this is with python 2.6.2 which is in the 2.x line of releases. So?
I gather that your example is about code that technically executes fine
with
both versions and produces the same result, i.e. that there is a subset
with
the
same syntax and semantics.
But 'print' calls that technically execute fine with both versions may
and
will
in general produce different results.
I.e. not just the syntax but also the semantics have changed:
>>> import sys
>>> sys.version
'2.6.4 (r264:75708, Oct 26 2009, 08:23:19) [MSC v.1500 32 bit (Intel)]'
>>>
>>> print( "2+2 =", 2+2 )
('2+2 =', 4)
>>> _
>>> import sys
>>> sys.version
'3.1.1 (r311:74483, Aug 17 2009, 17:02:12) [MSC v.1500 32 bit (Intel)]'
>>>
>>> print( "2+2 =", 2+2 )
2+2 = 4
>>> _
True. However, as someone else pointed out in a neighbouring thread you
can do
Python 2.6.2 (r262:71600, Aug 21 2009, 12:23:57)
[GCC 4.4.1 20090818 (Red Hat 4.4.1-6)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
from __future__ import print_function
print( "2+2 =", 2+2 )
2+2 = 4
which gives 100% compatibility as far as print is concerned between 2.6
and 3.x.
That makes the code behave with 3.x syntax and semantics regarding print.
I.e. it chooses one language.
It doesn't make them compatible:
Of course it makes them compatible. I'm not saying any print-related
code in python 2.6 is valid python 3 code, but that it is *possible*
to write print-related code in python 2.6 that is also valid in python
3.
if they were, then you wouldn't have to choose.
It seems to me you are arguing with the statement "Any print-related
python 2.6 code is valid python 3 code". Nobody is making this
statement. Let me repeat, what you should be arguing with is "It is
possible to write print-related python 2.6 code that is also valid
python 3 code". Perhaps I didn't make myself clear before, but at
least now I hope it's clear what I mean.
Perhaps we're in violent agreement. :-)
However, the root node of this subthread was my statement about the needless
incompatibility introduced by changing print in 3.x, whether that statement was
correct or reasonable / whatever.
The main problem with the incompatibility is for porting code, not for writing
code from scratch. It's also a problem wrt. learning the language. And I see no
good reason for it: print can't really do more, or less, or more conveniently
(rather, one has to write a bit more now for same effect).
Cheers,
- Alf
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