By popular demand, a few features commonly found in functional
programming languages and Lisp have been added to Python. With the
lambda keyword, small anonymous functions can be created.
Here's a function that returns the sum of its two arguments:
lambda a, b: a+b. Lambda forms can be used wherever function
objects are required. They are syntactically restricted to a single
expression. Semantically, they are just syntactic sugar for a normal
function definition. Like nested function definitions, lambda forms
cannot reference variables from the containing scope, but this can be
overcome through the judicious use of default argument values, e.g.
def make_incrementor(n):
return lambda x, incr=n: x+incr