Hello, world!

Loading...

En provenance du cours de Rice University

Python Programming Essentials

862 notes

Rice University

Python Programming Essentials

862 notes

Cours 1 sur 4 dans Specialization Introduction to Scripting in Python

This course will introduce you to the wonderful world of Python programming! We'll learn about the essential elements of programming and how to construct basic Python programs. We will cover expressions, variables, functions, logic, and conditionals, which are foundational concepts in computer programming. We will also teach you how to use Python modules, which enable you to benefit from the vast array of functionality that is already a part of the Python language. These concepts and skills will help you to begin to think like a computer programmer and to understand how to go about writing Python programs. By the end of the course, you will be able to write short Python programs that are able to accomplish real, practical tasks. This course is the foundation for building expertise in Python programming. As the first course in a specialization, it provides the necessary building blocks for you to succeed at learning to write more complex Python programs. This course uses Python 3. While many Python programs continue to use Python 2, Python 3 is the future of the Python programming language. This first course will use a Python 3 version of the CodeSkulptor development environment, which is specifically designed to help beginning programmers learn quickly. CodeSkulptor runs within any modern web browser and does not require you to install any software, allowing you to start writing and running small programs immediately. In the later courses in this specialization, we will help you to move to more sophisticated desktop development environments.

À partir de la leçon

Python as a Calculator

This module will expose you to Python so that you can run your first simple programs. You will use Python to compute the results of arithmetic expressions, as you would when using a calculator.

Course Overview3:32

Hello, world!3:05

Python Development Environments9:19

Rencontrer les enseignants

Scott Rixner
Professor
Computer Science
Joe Warren
Professor
Computer Science

I hope you are ready to get started and jump right in.

Before we start writing Python programs,

I want to show you a basic program that I've written and how one goes about running it.

Are you excited? Let's get started.

In all of the videos in this class,

we're going to use CodeSkulptor to run our Python programs.

CodeSkulptor is an online Python environment that we

developed specifically to make learning the program easier.

In order to open a file inside of CodeSkulptor,

all you have to do is navigate to a URL in your web browser.

So, if you click the link in this video,

you should be looking at the Hello, world!

Python program inside of CodeSkulptor in your web browser, just like I am.

Hello, world! is a very basic introductory program.

All it does is it prints out Hello, world!

saying hello to you.

So, how do we run this program?

In CodeSkulptor, we go over here,

and we click the run button.

And now, you will see that it says Hello, world!

to us in the output.

Congratulations, you've run your first Python program.

Now, I want to talk a little bit about the actual Python file that we just ran.

So, if you look over here in the code pane,

we have a bunch of lines of code here.

Up at the top of the file,

we have what is called a docstring.

A docstring is a description of the purpose of this file.

So, you can see there's a little explanation,

it says it's my first Python program, right?

And it's explaining what is in this file.

Now, you can see that this is surrounded by

triple quotes up here on the top and on the bottom,

and this indicates to Python that this is a docstring.

Next, we have a comment.

And you can see we have a three-line comment here.

Unlike docstrings, comments are not talking about the whole file,

rather they are giving you an explanation of

the small part of code that follows the comment.

So, this is describing what the line of code on line 11 is actually doing,

these comments here on lines 8 through 10.

You can see that the comments are prefaced with

these little hashtags that indicates to Python this is a comment.

And you can put anything that you want into these docstrings and comments,

they're for you to help you understand what's going on in the file and in

the program and help others who open up your file look at it as well.

Finally, down here, we have the actual line of Python code that's doing all the work,

and it says print("Hello, world!").

And we're going to go into much more depth on this in future videos,

but print is basically a function that

says take whatever you give it and put it into the output pane.

And what we're giving the print function is a string.

You can see it's in quotes, the string Hello, world!

Now, the print function, what it's doing?

It took that string, Hello, world!

and it put it over here in the output pane.

So, it did what we told it to do.

All right, there you have it.

Now, you've seen your first Python program.

You have a little bit of an understanding of exactly the structure of this program,

and you're able to run it.

In this video, I've shown you the basics of a simple Python file and how to run it.

Now, we need to start actually teaching you Python so you can write your own programs.

I hope I have whet your appetite for this and you're ready to go. See you soon.

Explorer notre catalogue

Rejoignez-nous gratuitement et obtenez des recommendations, des mises à jour et des offres personnalisées.

Coursera propose un accès universel à la meilleure formation au monde, en partenariat avec des universités et des organisations du plus haut niveau, pour proposer des cours en ligne.

© 2019 Coursera Inc. Tous droits réservés.

Télécharger dans l'App Store

Disponible sur Google Play