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Edwin Gonzales Melquiades
Edwin Gonzales Melquiades

Posted on • Updated on <time datetime="2021-01-19T10:30:54Z" class="date-no-year">Jan 19</time>

Lambda functions in Python

A lambda function is a small anonymous function that returns an object. This function is assigned to a variable o it is part of a function bigger.

Just as in a normal function the def keyword is needed, for lambda functions we need the lambda keyword.

The function lambda is more legible when we have to do small things.

Structure

The structure of the lambda functions is:

lambda args: expression

  • lambda: keyword to express that a function is a lambda function
  • args: are arguments separated for commas
  • expression: is an expression that returns an object

Examples

Here some examples for we obtain a better understanding of lambda functions.

Sum

sum = lambda x, y: x + y
total = sum(3, 5) // 8

Difference

difference = lambda x, y: x -y
value = difference(8, 5) // 3

Map

primes = [1, 2, 3, 5, 7]
primes_squared = map(lambda n: n*n, primes) // 1, 4, 9, 25, 49

Filter

numbers = [1, 2, 3, 5, 8]
odd = filter(lambda n: n%2 == 1, numbers) // [1, 3, 5]

It is my first post in Dev.to, I hope that it will be helpful for you.

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