> what is a lambda expression?
labmda is a reserved word and AFAIK it is an operatior.
By using lamba, you can create an anonymous function. That is, a
function without name.
For example, doing
def create_adder(amount):
def adder(x):
return x + amount
return adder
is equvalent to:
def create_adder(amount):
return lambda x : x + amount
In the former case:
>>> f1 = create_adder(4)
>>>f1
<function adder at 0x00BE6930>
>>> f1(2)
6
In the later case:
>>> f2 = create_adder(4)
>>> f2
<function <lambda> at 0x00BE66F0>
>>> f2(2)
6
For example, if you want create a new list by adding 4 to the elements
of another list:
>>> another = [1,2,3,4,5]
>>> newlist = map( lambda x: x+4 , another)
>>> newlist
[5, 6, 7, 8, 9]
Best,
Laszlo
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