In Python, a lambda function is a small anonymous function that can have any number of parameters, but can only have one expression. Lambda functions are used when you need a simple function for a short period of time and do not want to define a named function.

        Lambda functions are defined using the lambda keyword, followed by the input parameters and the expression to be evaluated. Here's an example:

multiply = lambda x, y: x * y
result = multiply(4, 5)
print(result)

        In this example, we define a lambda function called multiply that takes two input parameters (x and y) and returns their product. We then call the multiply function with the values 4 and 5, and assign the result to the variable result. Finally, we print the value of result, which is 20.

        Lambda functions are often used as arguments to higher-order functions, such as map, filter, and reduce. Here's an example of using a lambda function with filter to extract even numbers from a list:,

numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
even_numbers = list(filter(lambda x: x % 2 == 0, numbers))
print(even_numbers)


        In this example, we use a lambda function to define the condition for filtering the list of numbers. The lambda function takes one input parameter (x) and returns True if x is even (i.e., x % 2 == 0). We then pass this lambda function as the first argument to the filter function, which applies the lambda function to each element of the numbers list and returns a new list containing only the even numbers. Finally, we convert this new list to a Python list and print its contents.