Introduction to lambda functions
This tutorial explores lambda functions in Python, covering their syntax, usage, and advantages over traditional function definitions.
Let's start with a simple function that adds two numbers:
def add_numbers(a, b):
return a + b
That's the classical way of creating a function in Python.
However, Python provides another, more concise way to create functions using lambda functions.
A lambda function is an anonymous function expressed as a single statement.
The syntax of a lambda function is as follows:
lambda arguments: expression
There's the lambda keyword followed by a list of arguments, a colon, and then the expression that the function will evaluate and return.
The add_numbers function above can be expressed using a lambda function:
lambda x, y: x + y
You can see that lambda functions can be much more concise than defining a full function using the def keyword.
You can assign a lambda function to a variable, just like a regular function:
add = lambda x, y: x + y
result = add(5, 3)
print(result)
In this example, we assigned the lambda function to the variable add and then called it with arguments 5 and 3.
What will be the output?
multiply = lambda x, y: x * y
result = multiply(4, 5)
print(result)
Just like regular functions, lambda function can use variables that are defined outside their local scope.
Let's see an example:
x = 10
add_x = lambda y: x + y
result = add_x(5)
print(result)
In this example, the lambda function add_x takes one argument y and adds it to the variable x, which is defined outside the lambda function.
What will be the output?
x = 5
add_x = lambda y: x + y
result = add_x(5)
print(result)
What will be the output?
x = 5
add_x = lambda y: x + y
x = 10
result = add_x(5)
print(result)
What will be the output?
double = lambda x: x * 2
result = double(10)
print(result)