function expression with 2 arguments

[Xah Lee]

is there a way to write a expression of a function with more than 1
argument?

e.g., i want a expression that's equivalent to

def f(x,y)
return x+y

Xah
xah@xahlee.org

http://xahlee.org/PageTwo_dir/more.html

[Harlin Seritt]

Re: function expression with 2 arguments

Not exactly sure what you're looking for but you can do the following:

def dosomething(num list):
return numlist[0] + numlist[1]

numlist = [ 5, 10]
val = dosomething(num list)

If so, that would be somewhat pointless. It's always best to keep it
simple. It looks like the function you wrote above is very adequate for
the results you want returned.

[Reinhold Birkenfeld]

Re: function expression with 2 arguments

Xah Lee wrote:[color=blue]
> is there a way to write a expression of a function with more than 1
> argument?
>
> e.g., i want a expression that's equivalent to
>
> def f(x,y)
> return x+y[/color]

Looking for lambda?

Reinhold

[Peter Hansen]

Re: function expression with 2 arguments

Xah Lee wrote:[color=blue]
> is there a way to write a expression of a function with more than 1
> argument?
>
> e.g., i want a expression that's equivalent to
>
> def f(x,y)
> return x+y[/color]

Since assignment is a statement in Python, not an expression,
and since "def f" is an assignment that binds a function
object to the name "f", you can't do exactly what you've
asked for.

On the other hand, this should be about equivalent, though
it's not merely an expression:

f = lambda x, y: x + y

[Xah Lee]

Re: function expression with 2 arguments

lambda x, y: x + y

that's what i was looking for.

.... once i have a lambda expr, how to apply it to arguments?

e.g. in Mathematica
Function[#1+#2][a,b]

Python doc is quite confounded in it's way of organization centered
around implementation tied to hardware (as most imperative languages
are hardware-centric), as opposed to algorithm math concepts.

Xah
xah@xahlee.org

http://xahlee.org/PageTwo_dir/more.html

[Leif K-Brooks]

Re: function expression with 2 arguments

Xah Lee wrote:[color=blue]
> lambda x, y: x + y
>
> that's what i was looking for.
>
> ... once i have a lambda expr, how to apply it to arguments?[/color]

http://python.org/doc/current/ref/calls.html

[Xah Lee]

Re: function expression with 2 arguments

once i have a expresson of a function, how to apply it to arguments?

e.g. if i have
lambda x,y:x+y
i have to applied it to a,b in my code.

Xah
xah@xahlee.org

http://xahlee.org/PageTwo_dir/more.html

[Roel Schroeven]

Re: function expression with 2 arguments

Xah Lee wrote:[color=blue]
> once i have a expresson of a function, how to apply it to arguments?
>
> e.g. if i have
> lambda x,y:x+y
> i have to applied it to a,b in my code.[/color]

OK, I'll bite.

As with any other callable, you can simply call it like this:

a = 4
b = 24
(lambda x, y: x+y)(a, b)

Of course, you could just as well simply write

a+b

instead.

Most often the lambda is not used directly, but passed to a function. A
trivial example:

def f(fn, a, b):
return fn(a, b)

f(lambda x, y: x+y, 3, 42)

--
"Codito ergo sum"
Roel Schroeven

[Xah Lee]

Re: function expression with 2 arguments


Roel Schroeven wrote:[color=blue]
> (lambda x, y: x+y)(a, b)[/color]

Thanks. That's what i was looking for.

where in Pytho doc can one find this? or the lambda with multiple
params?

[color=blue]
> Most often the lambda is not used directly, but passed to a function.[/color]

That is because the IT morons has been throughly brainwashed by
imperative shits. (and these morons don't even know it)

i'll explain the ins and outs of expressions of functions some other
day.

Xah
xah@xahlee.org

http://xahlee.org/PageTwo_dir/more.html

[Peter Hansen]

Re: function expression with 2 arguments

Xah Lee wrote:[color=blue]
> Roel Schroeven wrote:
>[color=green]
>>(lambda x, y: x+y)(a, b)[/color]
>
> Thanks. That's what i was looking for.
>
> where in Pytho doc can one find this? or the lambda with multiple
> params?
>[color=green]
>>Most often the lambda is not used directly, but passed to a function.[/color]
>
> That is because the IT morons has been throughly brainwashed by
> imperative shits. (and these morons don't even know it)
>
> i'll explain the ins and outs of expressions of functions some other
> day.[/color]

After you read about them, I guess? We look forward to your
profound words on the subject.

Sheesh...

[Xah Lee]

Re: function expression with 2 arguments

PS sorry for the rude remarks out of nowhere.

Xah

[Steve Holden]

Re: function expression with 2 arguments

Xah Lee wrote:[color=blue]
> PS sorry for the rude remarks out of nowhere.
>
> Xah
>[/color]
Wow, signs of developing inter-personal skills. I must assume that
c.l.py is having its benign influence on you too!

regards
Steve
--
Meet the Python developers and your c.l.py favorites March 23-25
Come to PyCon DC 2005 http://www.pycon.org/
Steve Holden http://www.holdenweb.com/

[Xah Lee]

Re: function expression with 2 arguments



if i understand correctly, forms such as
(lambda x,y:x+y)(a,b)
can only be gained thru experience? and not documented directly
anywhere in the official docs?

Xah
xah@xahlee.org

http://xahlee.org/PageTwo_dir/more.html

[Leif K-Brooks]

Re: function expression with 2 arguments

Xah Lee wrote:[color=blue]
> if i understand correctly, forms such as
> (lambda x,y:x+y)(a,b)
> can only be gained thru experience? and not documented directly
> anywhere in the official docs?[/color]

The official documentation can't list every possible permutation of the
various syntactic constructs. It does explain parenthesis, the lambda
expression, and calling syntax; the particular combination of the three
that you're using can therefor be logically understood from the docs.

[Simon Percivall]

Re: function expression with 2 arguments

Actually, lambda forms are quite precisely documented at
http://docs.python.org/ref/lambdas.html if you feel than reading
the tutorial (specifically http://docs.python.org/tut/node6.html
section 4.7.5) is too base for you.