What is the benefit of this ' : ' in this code?

Question

def my_func(f, arg):
return f(arg)

👇
my_func(lambda x: 2*x*x, 5)

Answer 1

The lambda is just a function, like those you define with "def". They just don't have a name.
Before the colon (:) you put all the parameters (like with "def"), after it you put what the function does.

In other words,

def foo(x, y):
return x + y

and

foo = lambda x, y: x + y

are more or less the same thing.

Answer 2

thank u all☺