Job Ready Python

Lesson 21Using Lambdas

In this lesson, we will learn ways to analyze data to create meaningful business reports based on that data.

LEARNING OBJECTIVES

By the end of this lesson, you will be able to:

• Create lambda functions.
• Explain how a lambda function uses input values.
• Use a lambda function as part of a defined function.
• Use Python's map() function to apply a function to each element of an iterable object.
• Use Python's filter() function to identify specific elements in a collection that meet defined criteria and extract those elements to a new collection.
• Use Python's reduce() function to apply an operation sequentially to the elements in a collection.

Rather than creating a named function, it is sometimes useful to create a short function and embed it as part of a larger function. Lambda functions allow us to do this. A lambda function is a small anonymous function that allows us to create expressions within other functions.

Because iteration is a fundamental task in Python, there are several iteration functions that automatically move through a series of values in a collection, stopping only when the last value in the collection has been processed. There are a few key terms you should be aware of as you work through this lesson:

• Anonymous function: A function definition that is not bound to an identifier.
• Lambda function: An anonymous function that can take several arguments but can have only one expression.
• map(): The map() function returns a map object after ...