# Anonymous / Lambda Function

## Anonymous / Lambda Function

In Python, anonymous function is a function that is defined without a name.

• Normal functions are defined using the 'def' keyword.
• Anonymous functions are defined using the 'lambda' keyword.

• ## Rules of Lambda Function

• Lambda functions are small functions usually not more than a line.
• The body of lambda functions consists of only one expression.
• Lambda functions can have any number of arguments just like a normal function.
• The result of the expression is the value when the lambda is applied to an argument.
• There is no need for any return statement in lambda function.
• It cannot contain commands or multiple expressions.
• Lambda functions have their own local namespace and cannot access variables other than those in their parameter list and those in the global namespace.

• ## Syntax

```    lambda [arg1,arg2,....,argn]:expression
```

## Example 1: Normal Function

```# Function to adds two numbers and returns the output
return x + y

# Calling the Function

Output:
35
```

## Example 2: Lambda Function

```# Lambda Function to adds two numbers,returns the output and called through the variable
sum = lambda x, y: x + y

# call the lambda function
print("Sum of two numbers : ",sum(10,25))

Output:
Sum of two numbers :  35
```
• Here we are using two arguments x and y.
• Expression after colon is the body of the lambda function.
• Lambda function has no name and is called through the variable it is assigned to.

• (OR)

```# Lambda Function to adds two numbers and returns the output
(lambda x, y: x + y)(10,25)

Output:
35
```

## Example 3 :

```# Program to filter out only the odd items from a list
mylist = [1 , 5 , 15 , 22 , 58 , 98]
oddlist = list(filter(lambda x: (x%2 != 0), mylist))
print(oddlist)

Output:
[1, 5, 15]
```

## Example 4:

```# Program to display cube of each item in a list using map()
mylist2 = [1, 2, 3, 4, 5, 6, 7]
cubelist = list(map(lambda x: x ** 3, mylist2))
print(cubelist)

Output:
[1, 8, 27, 64, 125, 216, 343]
```
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