Python Lambda Function

Table Of Content:

Lambda functions are user-defined functions in Python, which have only a single statement to execute.
The Lambda function can have any number of arguments but only one expression, which is evaluated and returned.
As we know ‘def’ keyword is used to define a normal function, here, the ‘lambda’ keyword is used to define the Lambda function.
Lambda functions are the nameless function, which means they can be declared without a name.

lambda arguments: expression

arguments: This function can have any number of arguments.
expression: but only one expression, which is evaluated and returned.
Where ever a function object is required as an argument, you can use the Lambda function.

func = lambda a : print('Number Is:',a)

print(func)

print(func(5))

Output:
<function <lambda> at 0x000001F70A9CC700>
Number Is: 5

Note:

Here we have created a Lambda function that will print a number.
As Lambda functions are the nameless function, you need to assign them to some variable to store the function object.
You can use the function object to call the Lambda function.

func = lambda n : n * n

func(4)

Output:
16

func = lambda a,b,c: print(a+b+c)

func(3,4,5)

Output:
12

As we already know a map( ) function takes a function object as an argument, you can pass a lambda function to it.

numbers = [1,2,3,4,5,6]

cube = lambda n: n * n * n

mapping = map(cube,numbers)

number_cubes = list(mapping)

number_cubes

Output:
[1, 8, 27, 64, 125, 216]

Note:

As we already know a map( ) function takes a function object as an argument, you can pass a lambda function to it.

numbers = [1,2,3,4,5,6,7,8,9,10]

even = lambda n: n % 2 == 0

filtering = filter(even,numbers)

even_num = list(filtering)

even_num

Output:
[2, 4, 6, 8, 10]

Note: