Language design

[Chris Rebert]

* No explicit variable declarations (modulo `global`+`nonlocal`) means
that variable name typos can't be reliably detected at compile-time.
* The value of the loop variable at call-time for functions defined
within a loop trips people up.
* No self-balancing tree datatype of any kind is included in the std lib.
* Function scope rather than block scope (e.g. `while` doesn't
introduce a new scope) [Personally, I don't have much of a problem
with this, but some people do.]
* No anonymous block syntax (cf. Ruby or Smalltalk). Makes it
harder/uglier to define/use custom control structures. The `with`
statement would have been unnecessary.

Cheers,
Chris


On Mon, Sep 9, 2013 at 11:09 PM, Steven D'Aprano <steve at pearwood.info> wrote:
> Some time ago, Tom Christiansen wrote about the "Seven Deadly Sins of
> Perl":
>
> http://www.perl.com/doc/FMTEYEWTK/versus/perl.html
>
>
> What design mistakes, traps or gotchas do you think Python has? Gotchas
> are not necessarily a bad thing, there may be good reasons for it, but
> they're surprising.
>
> To get started, here are a couple of mine:
>
>
> - Python is so dynamic, that there is hardly anything at all that can be
> optimized at compile time.
>
> - The behaviour of mutable default variables is a gotcha.
>
> - Operators that call dunder methods like __add__ don't use the same
> method resolution rules as regular methods, they bypass the instance and
> go straight to the type, at least for new-style classes.
>
>
>
> --
> Steven
> --
> https://mail.python.org/mailman/listinfo/python-list