You'll learn how to write simple functions, as well as functions that accept multiple arguments and return multiple values. You'll also have the opportunity to apply these new skills to questions commonly encountered by data professionals and developers.

User-defined functions

Strings in Python

Recapping built-in functions

Write a simple function

Single-parameter functions

Functions that return single values

Multiple parameters and return values

Functions with multiple parameters

A brief introduction to tuples

Functions that return multiple values

Bringing it all together

Bringing it all together (1)

Bringing it all together (2)

Writing your own functions

You'll learn to write functions with default arguments so that the user doesn't always need to specify them, and variable-length arguments so they can pass an arbitrary number of arguments on to your functions. You'll also learn about the essential concept of scope.

Scope and user-defined functions

Pop quiz on understanding scope

The keyword global

Python's built-in scope

Nested functions

Nested Functions I

Nested Functions II

The keyword nonlocal and nested functions

Default and flexible arguments

Functions with one default argument

Functions with multiple default arguments

Functions with variable-length arguments (*args)

Functions with variable-length keyword arguments (**kwargs)

Default arguments, variable-length arguments and scope

Learn about lambda functions, which allow you to write functions quickly and on the fly. You'll also practice handling errors in your functions, which is an essential skill. Then, apply your new skills to answer data science questions.

Lambda functions

Pop quiz on lambda functions

Writing a lambda function you already know

Map() and lambda functions

Filter() and lambda functions

Reduce() and lambda functions

Introduction to error handling

Pop quiz about errors

Error handling with try-except

Error handling by raising an error

Bringing it all together (3)

Bringing it all together: testing your error handling skills

Lambda functions and error-handling

Tweets

It's time to push forward and develop your Python chops even further. Python has tons of fantastic functions and a module ecosystem. However, as a data professional or developer, you'll constantly need to write your own functions to solve problems that are dictated by your data. You will learn the art of function writing in this first course. You'll come out of this course being able to write your very own custom functions, complete with multiple parameters and multiple return values, along with default arguments and variable-length arguments. You'll gain insight into scoping in Python, be able to write lambda functions and handle errors in your function writing practice. You'll wrap up each chapter by using your new skills to write functions that analyze Twitter data.

Intermediate Python

Learn the art of writing your own functions in Python, as well as key concepts like scoping and error handling.

Python Data Science Toolbox (Part 1)

Introduction to Functions in Python

Associate Data Scientist  in Python

The keyword global

Introduction to Functions in Python

Exercise instructions

Hands-on interactive exercise