**kwargs?

[Francois De Serres]

All your **kwargs are belong to us.

*args is documented in the Tutorial. I reckon **kwargs represents a
dictionary of arguments. But I don't quite get the semantics of **x.
Undefined length tuple of undefined length tuples? Are there other
practical use cases for ** (common enough please, I wish I was, but I'm
not a scientist).

TIA,
Francois

[Roland Heiber]

Francois De Serres wrote:

All your **kwargs are belong to us.

*args is documented in the Tutorial. I reckon **kwargs represents a
dictionary of arguments. But I don't quite get the semantics of **x.
Undefined length tuple of undefined length tuples? Are there other
practical use cases for ** (common enough please, I wish I was, but I'm
not a scientist).

TIA,
Francois

Assume d = { 'arg1':'value1','arg2':'value2' }. Then

func(**d)

is the same as:

func(arg1='value1', arg2='value2')

HtH, Roland

[Peter Hansen]

Francois De Serres wrote:

All your **kwargs are belong to us.

*args is documented in the Tutorial. I reckon **kwargs represents a
dictionary of arguments. But I don't quite get the semantics of **x.
Undefined length tuple of undefined length tuples? Are there other
practical use cases for ** (common enough please, I wish I was, but I'm
not a scientist).

Where did you get "tuples of tuples" for **x ? It doesn't have tuples
at all, but is merely a dictionary, as you said in the first place. Are
you implying you think **kwargs and **x are somehow magically different?

-Peter

[Michael Hoffman]

Peter Hansen wrote:

Francois De Serres wrote:

*args is documented in the Tutorial. I reckon **kwargs represents a
dictionary of arguments. But I don't quite get the semantics of **x.
Undefined length tuple of undefined length tuples? Are there other
practical use cases for ** (common enough please, I wish I was, but
I'm not a scientist).

Where did you get "tuples of tuples" for **x ?

I would guess it is confusion from languages where unary * means
dereference and ** means double dereference.

To the OP: I'm glad you have been reading the tutorial. If you have
further questions the reference manual is a good place to look:

http://docs.python.org/ref/function.html

Just as you can use a name other than self as the first argument to an
unbound method, you can call your *args and **kwargs *x and **y instead,
but they will still act just like *args and **kwargs.

The stars are magic, not the names.
--
Michael Hoffman

[Francois De Serres]

Michael Hoffman wrote:

Peter Hansen wrote:

Francois De Serres wrote:

*args is documented in the Tutorial. I reckon **kwargs represents a
dictionary of arguments. But I don't quite get the semantics of **x.
Undefined length tuple of undefined length tuples? Are there other
practical use cases for ** (common enough please, I wish I was, but
I'm not a scientist).

Where did you get "tuples of tuples" for **x ?

I would guess it is confusion from languages where unary * means
dereference and ** means double dereference.

That was precisely my mistake.
To the OP: I'm glad you have been reading the tutorial. If you have
further questions the reference manual is a good place to look:

http://docs.python.org/ref/function.html

Now I see, there's a '**' token, which is not the same as two adjacents
'*' tokens.
Just as you can use a name other than self as the first argument to an
unbound method, you can call your *args and **kwargs *x and **y instead,
but they will still act just like *args and **kwargs.

The stars are magic, not the names.

Thanks mucho!
F.