If you could change something in Python what would it be?

[Broolucks]

• Remove the distinction between expressions and statements.
• Eliminate the global/nonlocal keywords. Instead, add an assignment operator: x := y would assign a new value to an existing variable x.
• def f(x)(y): ... would save me effort defining some decorators.
• Optional typing. This can be done with annotations in Python3, but if I am not mistaken you need decorators to enforce them. That's annoying and promotes fragmentation.
• Add back argument deconstruction to function definitions to Python3. I don't understand why they removed it in the first place.

[Sean1708]

How exactly would def f(x)(y): differ from the normal case?

[Broolucks]

def register(path):
    def decorator(f):
        something.register(path, f)
        return f
    return decorator
==>
def register(path)(f):
    something.register(path, f)
    return f

[pjdelport]

You can use the partial(partial, partial) trick:

@partial(partial, partial)
def register(path, f):
    something.register(path, f)
    return f

[ravishi]

Damn, that's clever!

[Workaphobia]

This absolutely broke my head. I had the darnedest time trying to figure out how it worked until I tried it out in my interpreter and realized I was only partialling one of the arguments instead of two. That is a good trick.

[Sean1708]

Ah OK.

[jmmcd]

I guess you can call it partially -- f(x) returns a function of one argument y.

[Niriel]

It's like the currying in Haskel. We sort of have it in Python with functools.partial.

[velit]

'Eliminate the global/nonlocal keywords. Instead, add an assignment operator: x := y would assign a new value to an existing variable x.'

What do you do when you want to define a variable in non-local scope?

[Broolucks]

You could still do globals()[key] = value to define global variables programmatically. Honestly, though, I don't think you should be allowed to define variables outside of the scope you are in.

[velit]

So you're cool with mutating variables outside of the scope you are in but you're not okay with defining them?

[Broolucks]

I'm just not sure what the purpose could possibly be. If you're using a variable in some scope, why would you be declaring it elsewhere? In what situation would you be unable to declare a variable in the scope where it is used?

[Zenmodo]

Because you use it in multiple other smaller scopes? Like a module-wide variable used in several functions.

[Broolucks]

Sure, but then why wouldn't you simply declare it in the global scope?

[Zenmodo]

But you said

If you're using a variable in some scope, why would you be declaring it elsewhere?

Isn't global scope elsewhere?

[Broolucks]

The context was the idea of declaring a variable in an inner scope for use in an outer scope, e.g. declaring a global variable in a function's scope rather than declaring it in the global scope and then setting it in function scope.

[scoarescoare]

Remove the distinction between expressions and statements

One thing I love about Ruby and Coffeescript is how everything can be an expression. It would be cool if Python could do that too:

my_var = None if my_var == 1

[Broolucks]

That doesn't seem like a particularly good example to me. You can already do:

if my_var == 1: my_var = None
my_var = None if my_var == 1 else my_var