## DEV Community

Rahul Banerjee

Posted on • Originally published at realpythonproject.com

# #Day12 - Anonymous Functions in Python

Today, we will be talking about anonymous functions in Python. Anonymous functions are also known as lambda functions. They are one-liners and look elegant. Below is the syntax

``````lambda parameters: expression
``````

Since they have no names, they are called anonymous functions. However, to actually use them, we need to assign them to a variable

``````variable = lambda parameters: expression
``````

To call a lambda function, we just call the variable and pass the parameters

``````variable(parameters)
``````

Let's look at an example and compare a function written as a normal function and as a lambda function

#### Normal

``````def square(x):
result = x*x
return result

ans = square(5)
print(and)
``````

#### Lambda

``````square = lambda x: x*x
ans = square(5)
print(and)
``````

Both print the same result. However, the lambda expression looks cleaner.

#### Lambda functions with multiple parameters

``````add = lambda x,y: x+y
``````

### Using lambda functions with the sorted function

``````pairs = [(1,2) , (3,14) , (5,26) , (10,20) ]

sorted_pairs = sorted(pairs, key = lambda pair: max(pair[0],pair[1]))
print(sorted_pairs)
``````

We have a list of tuples and want to sort it in ascending order based on the maximum number in the pair.

### Parameterless lambda function

``````func = lambda : return "String"
print(func())
``````

#### Lambda Function without variable name

``````print( (lambda x,y: x+y)(4,5))
``````