On 12/27/2011 8:36 PM, Hitesh Kumar wrote:
I really don't get it. What is lambda? I keep seeing it and I couldn't
understand anything online about it.
lambda
An anonymous inline function consisting of a single /expression/
<#term-expression> which is evaluated when the function is called.
The syntax to create a lambda function is lambda [arguments]: expression
It is a way to create a simple anonymous function.
func = lambda x, y : x + y
is the equivalent of
def func(x, y):
return x = y
Handy when the function returns an expression (no compound statements)
and does not need a name, e.g.
map(lambda x, y : x + y, (1,2,3), (4,5,6))
OK now you wonder what is map so:
map(/function/, /iterable/, /.../)
Apply /function/ to every item of /iterable/ and return a list of
the results. If additional /iterable/ arguments are passed,
/function/ must take that many arguments and is applied to the items
from all iterables in parallel. If one iterable is shorter than
another it is assumed to be extended with None items. If /function/
is None, the identity function is assumed; if there are multiple
arguments, map() <#map> returns a list consisting of tuples
containing the corresponding items from all iterables (a kind of
transpose operation). The /iterable/ arguments may be a sequence or
any iterable object; the result is always a list.
>>> print map(lambda x, y : x + y, (1,2,3), (4,5,6))
[5, 7, 9]
--
Bob Gailer
919-636-4239
Chapel Hill NC
_______________________________________________
Tutor maillist - Tutor@python.org
To unsubscribe or change subscription options:
http://mail.python.org/mailman/listinfo/tutor
