Are the critiques in "All the things I hate about Python" valid?

[bartc]

On 20/02/2018 12:11, Paul Moore wrote:
> On 20 February 2018 at 11:18, Antoon Pardon <antoon.pardon at vub.be> wrote:

>> There is no such possibility in Python. You can off course start with x
>> = Digit(5), but the language
>> won't stop you from doing x = 11 later.

>> I'm not proficient with C++, but IIUC, you could make a class in C++ and
>> have the constructor and
>> copy operator check for these kind of things. True it would be run-time
>> checks but that would
>> already be more than Python can give.

I don't know if that counts. In Pascal (and presumably Ada) then all the 
gubbins need to make this work properly:

   var x: 1..10;

   x = 10;
   x = x + 1;   { error? }

would already be in place. Trying to emulate that within a language is 
complex and unwieldy, and someone has to know how to do it, and then do 
it. If someone else creates an add-on for it, then those tend to be 
large and cumbersome (because they have to have every conceivable bell 
and whistle). And it's an extra dependency.

The end result: if I wanted to sit down right now and have a variable 
and/or type in Python or C++ that is constrained to be within 1..10, 
then I couldn't. I'd have to use a generic integer type.

And in fact, in Python, I couldn't even do that, as I can assign 
anything at all to x.

This is not necessarily undesirable: part of the point of dynamic 
languages is being informal and having less discipline imposed so that 
things can get done more rapidly. But enforced discipline can also be 
useful.

> It's somewhat unrelated (scoping is a different topic than assignment)
> but you can do
> 
> {
>      int x = 2;
>      {
>          char *x = "hello";
>      }
> }
> 
> in C, so names can have different types even in C (it's just
> variables, or names within a specific scope, that have types
> associated with them).

That's scope; Python has that too. (Although not C's block scopes and 
its bizarre rules which mean that you can have up 5 different 'x' 
meanings even within the same block. And an unlimited number of 'x' 
scopes within the same function.

(This is allowed in C:   int L; L: L=10; goto L; )

-- 
bartc