43 Lambda function in Python

 

'''

1. Lambda is a another way to create a function.

2. Lambda is a one line anonymous function it doesn't contains name.

3. Using lambda we can do only one expression.

'''

## Lambda with out arguments

#add = lambda : 3 + 5

#r = add()

#print(r)

## Lambda with arguments 

#add = lambda a,b: a + b

#r = add(2, 33)

#print(r)

## Lambda with if and else

add = lambda a,b: a + 10 if a > 5 else b + 100

print(add(6,6))

------lambda with Map-----

# Double the value of each element

myList = [10, 25, 17, 9, 30, -5]

myList2 = map(lambda n : n*2, myList)

print myList2

------lambda with filter------

# Filters the elements which are even numbers

myList = [10, 25, 17, 9, 30, -5]

myList2 = list(filter(lambda n : (n%2 == 0), myList))

print(myList2)

------Use lambda function with filter()-----

The Python built-in filter() function accepts a function and a list as an argument. 

It provides an effective way to filter out all elements of the sequence. 

It returns the new sequence in which the function evaluates to True.

#program to filter out the tuple which contains odd numbers    

lst = (10,22,37,41,100,123,29)  

oddlist = tuple(filter(lambda x:(x%3 == 0),lst))     

print(oddlist)  

-----Using lambda function with map()-----

The map() function in Python accepts a function and a list. 

It gives a new list which contains all modified items returned by 

the function for each item.

lst = (10,20,30,40,50,60)  

square_list = list(map(lambda x:x**2,lst))     

print(square_tuple)