[Tutor] map, filter and lambda functions
Thu, 23 Aug 2001 17:17:56 +0100
> > You could define functions:
> > def stripitem(x): return string.strip(x)
> > def upperitem(x): return string.upper(x)
> Same for the last two here. You might as well write
> stripitem = string.upper
Sure, I was just making the point that in general
foo = lambda x: <expr>
can be replaced by
def foo(x): return <expr>
THe case where <expr> is a standard function just
happens to be a special case where the def is done for you.
> > You can always replace a lambda with a function in Python,
> > but in this case the lambda is probably clearer by putting
> > the action explicitly in the operation.
> Except that the lambda does no action it all, so it's obfuscating :)
Its still less obfuscating than passing a user defined function might be.
Despite the friendly name 'upperitem' we don't really know whether its
a wrapper for string.upper or math.ceil or something we wrote ourselves.
At least the lambda in this case exposes the function used. Which, again,
was the gerneral point I was trying to make about the use of lambdas.