> On 24 Dec 2018, at 11:21, 李默 <phyl...@163.com> wrote:
>
> I am having an idea on loosing the argument validity check when passing the
> function arguments in keyword way.
> For example:
> -------------------------------
> def f(x, y):
> print(x, y)
> def call_f():
> f(x=7, y=9, z=9)
>
> call_f()
> ------------------------------
> In the current of python, the extra pass of 'z' would let the interpreter
> raise an exception and stop work. My idea is that the interpreter need not
> stop because all the needed args are completely provided. Of course for this
> toy example, 'f' can be define as f(x, y, **kwargs) to achieve the same
> goal. However, essentially it is reasonably to keep interpreter going as
> long as enough args are passed. And this modification can bring more freedom
> of programming.
Similar features exists in JavaScript (where you can also do the same thing
with positional arguments), and Clojure to make two.
I personally think this is extremely bad. This type of behavior can make error
in your code slip by undetected for a very long time. Let's take a concrete
example! We have a function:
def foo(*, a, b=3, c):
....
People call it like so:
foo(a=7, b=1, c=11)
Now what happens if we rename argument b to q? The above code still runs! It
just now passes 3 (the default value) to foo instead of the intended 1.
I hope this example is enough to convince you of the danger of such a feature.
It's certainly the reason why I think JavaScript and Clojure are terrible when
it comes to passing arguments :)
Best regards
Anders_______________________________________________
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