What are lambda functions used for in Python?

Question

I was recently trying to complete the Average Word Length code coach challenge when a friend of mine suggested I used this code:

sentence = input()
filtered = ''.join(filter(lambda x: x not in '".,;!-', sentence))
words = [word for word in filtered.split() if word]
avg = sum(map(len, words))/len(words)
print(avg)

Since I’m new at Python, and I don’t know anything about lambda functions, it got me wondering what they’re are used for. I hope I can get some more insight about them with your help.

Solo Learn’s code testing utility ended up rejecting the code so don’t even bother using it to complete the challenge.

Answer 1

Hey CinnamonOne,

Lambda functions are simply functions that do not exceed a single line (but can be used for complex functionality too).

For example, consider the below code for getting a square of a number
______________________________
Code using normal function:

def square(number):
return number * number
____________________________
Code using Lambda function:

square = lambda number: number * number
_____________________________

Where number is used as a variable here.

As you can see here the code becomes more readable and reduces the number of lines.

Answer 2

Lambda functions are also called anonymous functions as they don't require a name. They fulfil the functionality of a normal function but are quiker, shorter and easier to write. They are great for mapping list and filtering lists but also just great to write a quick disposable function in one line.

Here you can learn more..
https://www.programiz.com/JUMP_LINK__&&__python__&&__JUMP_LINK-programming/anonymous-function

Answer 3

To make one liner functions
Makes your code look smaller
Hence, it is used for making codes of good designs
Moreover, lambda is used for creating anonymous functions that are used extensively with 'map' / 'filter'