[Tutor] can someone explain to me Lambda functions/statements, preferably with examples, I don't get it
Wed, 23 Aug 2000 05:41:12 -0500 (EST)
Lambda is used to make a 'quick' function:
You could create a 'normal' function say foo:
return x - 3*x + 4*x**2
and then use foo in another situation where a function is required:
print map(foo, [1,2,3,4,5])
would result in: [2, 12, 30, 56, 90]
a shorter definition would be using lambda (same function)
bar = lambda x : x - 3*x + 4*x**2
print map(bar, [1,2,3,4,5])
would produce the same result...
of course, now you could just skip defining 'bar' and use
the function directly in the 'map'...
print map(lambda x : x - 3*x + 4*x**2, [1,2,3,4,5])
and get the same result again...
lamda x, y, z, .... : (single line fuction of x, y, z ...)
is equivalant to:
def foo(x, y, z, ...):
return (same single line function of x, y, z, ...)
except the lambda version doesn't have (or need) a 'name'.
does that help?