Lamdba forms

[lsmith234@gmail.com]

hi all, I am a python newbie. why functions created with lambda forms
cannot contain statements?
how to get unnamed function with statements?

[Terry Reedy]

Re: Lamdba forms


<lsmith234@gmai l.com> wrote in message
news:1145492986 .738200.229690@ i39g2000cwa.goo glegroups.com.. .[color=blue]
> hi all, I am a python newbie. why functions created with lambda forms
> cannot contain statements?[/color]

Because statement do not fit in expressions.
[color=blue]
> how to get unnamed function with statements?[/color]

Can't.

Many discussions in archives (which Google has).

tjr

[Paddy]

Re: Lamdba forms

To expand on the above, Python does not have statements in its lambda
forms, but that does not stop pythoneers from getting the job done.

I use a named function for that, but if you have an issue with that, it
really is worth following Terry's advice as the subject has been
tackled at great length before.

- Cheers, Paddy.

[Ant]

Re: Lamdba forms

Why does the function have to be unnamed? you can easly nest function
definitions and refer to them. IIRC the lambda form is probably going
to be removed at some point, as it is not needed:

def outerfn():
dostuff()
def inner(x,y):
out = (x^y)
print out
return out

my_local_functi on = inner
my_local_functi on(3,4)

outerfn()

[Duncan Booth]

Re: Lamdba forms

Ant wrote:
[color=blue]
> IIRC the lambda form is probably going
> to be removed at some point, as it is not needed:[/color]

You remember incorrectly.

[Ant]

Re: Lamdba forms

No, I remembered correctly:

http://www.artima.com/weblogs/viewpost.jsp?thread=98196

but probably not until Python 3.0.

[Fredrik Lundh]

Re: Lamdba forms

"Ant" wrote:
[color=blue]
> No, I remembered correctly:
> http://www.artima.com/weblogs/viewpost.jsp?thread=98196
> but probably not until Python 3.0.[/color]

however,

http://mail.python.org/pipermail/python-dev/2006-February/060415.html

(one would have thought that someone might have added a note to
the comments of the first post, but the most recent contributor to
that thread is a mortgage spammer...)

</F>

[Ant]

Re: Lamdba forms

Fair enough. I've just found this as well, which implies that lambda
isn't being killed off in 3.0:

http://www.python.org/dev/peps/pep-3100/

In particular:
"Lambdas will have to be parenthesized [23]"

[Duncan Booth]

Re: Lamdba forms

Ant wrote:
[color=blue]
> Fair enough. I've just found this as well, which implies that lambda
> isn't being killed off in 3.0:
>
> http://www.python.org/dev/peps/pep-3100/
>
> In particular:
> "Lambdas will have to be parenthesized [23]"
>[/color]

Also: http://www.python.org/doc/essays/ppt...6/Py3kACCU.ppt
slide 14.