Python is readable

Kiuhnm kiuhnm03.4t.yahoo.it
Thu Mar 15 15:16:31 CET 2012


On 3/15/2012 13:21, Chris Angelico wrote:
> On Thu, Mar 15, 2012 at 10:59 PM, Kiuhnm
> <kiuhnm03.4t.yahoo.it at mail.python.org>  wrote:
>> On 3/15/2012 12:47, Chris Angelico wrote:
>>> It's a little odd, perhaps, if seen in a vacuum. But everything counts
>>> from zero - list indices, etc - so it makes sense for range(len(lst))
>>> to return indices valid for lst.
>>
>> Maybe range uses [...) intervals? So range(a,b) is a,a+1,a+2,...,b-1 and
>> range(b) is just short-hand for range(0,b)?
>
> Yup. It's amazing how accurate your conjectures are - it's almost like
> you've been reading the docs! :D

Come on... that was easy! :)

> But yeah, that's pretty logical IMHO;
> and having gotten used to [) intervals in many areas of computing,
> I've come to find [] intervals disconcerting. Bible passages are
> described as, for instance, John 14:5-7, which is a three-verse
> passage (5, 6, 7), even though 7-5=2.

Common people use mainly inclusive intervals as far as I can tell.
For instance, "from" and "to" are inclusive.
They could tell you they don't like your intervals because 8-5+1 = 4 
instead of 3.

> However, inclusive-inclusive intervals have the benefit that they
> don't require the element "beyond the last" to be indexable. This is
> important if you're working with something that takes up all of
> addressable memory - going back to the IBM PCs on which I learned to
> code, you could use one 64KB segment for an array, but then there's no
> way for a 16-bit integer to indicate "past the end".

But you lose the empty interval (a,a). You're forced to use (a,a-1) or 
something similar. There's always a drawback.

>>> List comps are pretty readable if you know how programming languages
>>> work. Python need not be readable by everyone and his grandmother, and
>>> it does a fairly good job of being grokkable to someone who has a few
>>> ranks in Coding. (Yeah, I'm a D&D nerd. )
>>
>> I like what I've seen so far.
>
> Python has its problems, but it's a good language. I personally prefer
> to delimit blocks of code with braces than with indentation,

I, on the other hand, prefer indentation. I find braces redundant (in 
fact, I never use them in pseudo-code).

> and I
> also prefer explicit declaration of variables (yes, it's extra work,
> but you can have infinitely nested scopes and easily-caught syntax
> errors when you misspell one), but they're relatively minor.

I usually declare my variables but close to where I need them.

> One of my
> favorite aspects of Python is that *everything* is an object. There's
> no magic syntax that gives you a piece of an object, or something
> special about variables that contain this, that, or the other. A
> literal list [like, this, one] can be used in exactly the same ways as
> the name of a variable containing a list or a function call returning
> a list - there is no difference. Oh how I yearn for that when working
> in C++ or PHP!

Don't worry. Soon you'll be using C++0x :)))

Kiuhnm



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