lambda function in python

 lambda function in python is used to create function without name(annonymous function). its one line function

 syntax:

lambda p1,p2,p3...pn :expression
you can read ':' as 'such that' as  in set builder method 

note:

p1,p2...pn = function parameters
there can be only one expression
lambda function by itself  returns  a function object

example

sum=lambda a,b:a+b

print(sum(1+2))
output 
3

x=1
print(lambda x :  print(x))
output:
<function <lambda> at 0xsomeaddress>

we need to call function object to get result 

IIFE stands for immediately invoked function execution
syntax::
(lambda parameter: expression)(argument)
example>>
(lambda x :  print(x**2))(9)

note:
lambda function is treated as normal function by python interpreter