"just like Java" (was :Re: translating Python to Assembler)

[Bruno Desthuilliers]

Paul Boddie a écrit :
> On 25 Jan, 14:05, Bruno Desthuilliers <bruno.
> 42.desthuilli... at wtf.websiteburo.oops.com> wrote:
>> Christian Heimes a écrit :
>>
>>> No, that is not correct. Python code is compiled to Python byte code and
>>> execute inside a virtual machine just like Java or C#.
>> I'm surprised you've not been flamed to death by now - last time I
>> happened to write a pretty similar thing, I got a couple nut case
>> accusing me of being a liar trying to spread FUD about Java vs Python
>> respective VMs inner working, and even some usually sensible regulars
>> jumping in to label my saying as "misleading"...
> 
> Well, it is important to make distinctions when people are wondering,
> "If Python is 'so slow' and yet everyone tells me that the way it is
> executed is 'just like Java', where does the difference in performance
> come from?" Your responses seemed to focus more on waving that issue
> away and leaving the whole topic in the realm of mystery. The result:
> "Python is just like Java apparently, but it's slower and I don't know
> why."

I'm afraid you didn't read the whole post :

"""
So while CPython may possibly be too slow for your application (it can 
indeed be somewhat slow for some tasks), the reasons are elsewhere 
(hint: how can a compiler safely optimize anything in a language so 
dynamic that even the class of an object can be changed at runtime ?) ."""

I may agree this might not have been stated explicitily enough, but this 
was about JIT optimizing compilers. Also, a couple posts later - FWIW, 
to answer the OP "how does it comes it slower if it's similar to Java" 
question :

"""
Java's declarative static typing allow agressive just-in-time
optimizations - which is not the case in Python due to it's higly
dynamic nature.
"""