lmbda

4.7.5. Lambda Expressions
Small anonymous functions can be created with the lambda keyword. This function returns the sum of its two arguments: lambda a, b: a+b. Lambda functions 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 functions can reference variables from the containing scope:

def make_incrementor(n): return lambda x: x + n
f = make_incrementor(42)
f(0)
42
f(1)
43
_________ The above example uses a lambda expression to return a function. Another use is to pass a small function as an argument:

pairs = [(1, ‘one’), (2, ‘two’), (3, ‘three’), (4, ‘four’)]
pairs.sort(key=lambda pair: pair[1])
pairs=[(4, ‘four’), (1, ‘one’), (3, ‘three’), (2, ‘two’)]