Why I hate lambdas (Re: Do any of you recommend Python as a first programming language?)

[Roy Smith]

Steven D'Aprano <steve at REMOVE-THIS-cybersource.com.au> wrote:

> On Sun, 23 Mar 2008 13:51:34 -0400, Roy Smith wrote:
> 
> > On the other hand, when I do:
> > 
> > def torture():
> >     woman.putInChair()
> >     cushion.poke()
> >     rack.turn()
> > 
> > I've also done two things.  First, I've created a function object (i.e.
> > a lambda body), and I've also bound the name torture to that function
> > object, in much the same way I did with the list.  But, it's different. 
> > The function object KNOWS that it's name is torture.
> 
> No it does not. Function objects don't know their name. All they know is 
> that they have a label attached to them that is useful to use as a name 
> in some contexts, e.g. when printing tracebacks. It's just a label, 
> nothing more.

I think we're arguing the same thing.  When you write

def foo():
   whatever

you create an object which contains the string "foo", retrievable through 
its __name__ attribute.  That's what I meant by "it knows its name"

>> What Python give us with lambdas is some half-way thing.  It's not a
>> full function, so it's something that people use rarely, 
> 
> Which people?
> 
> > which means most people (like me) can't remember the exact syntax. 
> 
> Speak for yourself, not for "most people".

Well, OK.  When I said, "most people", I really meant "I know about me, and 
I'm guessing about other people".  I still think it's a fair statement that 
if you look any large collection of Python code, you will find many more 
uses of def than of lambda.

> > Even when I know
> > it's the right thing to be using in a situation, I tend not to use it
> > simply because the path of least resistance is to write a one-off
> > function vs. looking up the exact syntax for a lambda in the manual.
> 
> lambda arguments : expression
> 
> Why is that harder to remember than this?
> 
> def name ( arguments ) :
>     block  

because I remember things I use often, better than I remember things I use 
infrequently.