Beginner needs advice

[harrismh777]

Ethan Furman wrote:
> Um -- how can you have on the one hand "completely not compatible" and
> on the other "code that can cross-execute on either version"?

Great question ! .. .it has to do with education.

... if you learn 2.x (only) and attempt to program on the 3.x platform, 
(without helps, education, migration tools, etc) you will fail... and 
you will be frustrated. Why? 3.x is not compatible with 2.x knowledge.

    If you learn 3.2 (only) and attempt to program on 2.x you will fail, 
and you will be frustrated. Why?   Because the two languages are 
different and incompatible.

Now then, can you learn both?...  sure.    Can you migrate one to the 
other with enough knowledge and effort?... yup.   Is it possible (with 
enough cleverness) to write code that will run on "both" without 
modification... yes...   Are the two languages compatible?    No!


Where this really counts of course is real-world apps. It is relatively 
easy to write trivial code blocks that demonstrate that nothing has 
changed in 3.x/   ... and they are *all* misleading.  The truth is that 
hundreds of details have changed making the two 'versions' actually 
different languages.


If I use the '89 version (1) K&R to write a C program,  and compile it 
on the current gcc without mods it will run.  If I use the 2.5 python 
manual to write a python program and try to run it on 3.2 it will fail 
(for many, many reasons).  This is my definition of completely 
incompatible. The two languages are different; period.

The problem is that they "look" similar.     :)



kind regards,
m harris