Lambda Functions in Python

Ever heard of something called Anonymous functions? An anonymous function in Python is a function that is defined without a name.

While functions in Python are defined using the def keyword, anonymous functions are defined using the lambda keyword. Hence, they are also called lambda functions.

Syntax of Lambda functions

lambda argument: expression

argument - The argument to pass into
           your lambda function 

Code

# Normal Function
def return_squared(x):
    return x**2

# Lambda Function
return_squared = lambda x : x**2

Notice, the absence of a function name in the Lambda function. Also, the def keyword is replaced with a lambda keyword.

lambda x: x**2 is the lambda function. Here x is the argument and x**2 is the expression that gets evaluated and returned as a function object.

It’s also easy to call lambda functions.

Here is the difference between a normal function in Python vs a Lambda function.

# Normal Function
def return_squared(x):
    return x**2

result = return_squared(5)
print(result)

# Lambda Function
return_squared = lambda x : x**2

result = return_squared(5)
print(result)

Output

25
25

Multiple arguments with lambda function

You can provide as many arguments you want with lambda function.

Code

addition = lambda x,y:x+y
print(addition(5,3))

Output

8

Advantages of Lambda functions

1. Fewer Lines of Code.
2. Can be easily used with filter, map and reduce methods.

Check out my YouTube video on lambda Function to get a better understanding of the concept.