07_lambdas.md

Day 07 - Lambdas

Lambda functions are also known as anonymous functions, they can, as a normal function, take different arguments and return a single value, but lambdas are one-line functions.

The syntax is as follows:

lambda arguments: expresion

Example

def normal_multiply(num_a, num_b):
    return num_a * num_b

lambda_multiply = lambda num_a, num_b: num_a * num_b

print(normal_multiply(5, 2))
print(lambda_multiply(5, 2))

# Output:
# 10
# 10

As you can see both normal_multiply and lambda_multiply functions, another difference you can notice is that lambda functions return a value without explicitly using the return keyword.

Why use Lambda functions?

We can create functions that perform a simple actions or operations using lambda functions, so that we can make our code more compact and simple.

Let's try using the lambda functions with one of the previous examples.

Filter example

def multiple(number):
    return number % 2 == 0

numbers = range(1, 101)
filter_numbers = filter(multiple, numbers)
print(list(filter_numbers))

Using lambda function

numbers = range(1, 101)
filter_numbers = filter(lambda number: number % 2 == 0, numbers)
print(list(filter_numbers))

When you understand the syntax of these functions, you will see that they are really easy to use and can be very useful.

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