How to create Lambda Expressions

Lambda Expressions

lambda expressions are small, unnamed functions that can only contain an expression, and return its value. A lambda expression is written like this:

lambda x, y, z: x + y + z 

The first word, lambda, is a reserved word. It is followed by the parameters, a colon ( :), and the body.

bigger = lambda a, b : a > b

print bigger(1,2)
print bigger(2,1)

The code above generates the following result.

The map function "maps" one sequence into another by applying a function to each of the elements.

For example, you may have a list of numbers, and you want to create another list in which all the numbers are doubled:

numbers = [2, 1, 10, 8, 11] 
map(lambda n: 2*n, numbers) 

lambda function as a list number

L = [(lambda x: x**2), (lambda x: x**3), (lambda x: x**4)]
# from w w w .ja  va 2  s. com
for f in L:
    print f(2)     # prints 4, 8, 16

print L[0](3)      # prints 9

The code above generates the following result.