[MUSIC].

So, at this point in the class, we've introduced you to CodeSkulptor, and we've

shown you a little bit of Python. However, we haven't shown you how to save

anything. So, if every time you go back to

CodeSkulptor, you have to retype in your work, that's going to get really tedious,

really fast. So, today, we're going to talk about

saving things and how to get them back into CodeSkulptor.

Okay. Let's head over to CodeSkulptor.

Here we are. And for the purposes of today, I don't

want to use the example program. Instead I just want to type my own.

[SOUND] It's my first program. Print, hello.

Right? I've got this fantastic program.

I run it. Does what I expect.

Now I want to save it because I'm happy with it.

Well, how do I do that? You can see up here in the control par-,

part of the application that there is an icon with a disk.

And that is the Save button. I pushed it.

Looks like nothing happened. Well, actually, something did happen.

The address in the address bar is changed.

And if you look up here, you can see that now at the end of the URL, is this

hashtag and its filename. This filename was randomly generated for

you. This now names your file in the Cloud.

When you push the Save button, your file is sent off to the Cloud.

A new randomly generated filename is, is created for you, and it is part of the

URL. So, this URL will now, and until the end

of the class, name your file. Okay?

So what does that mean? It means I can copy this URL.

I can create a new tab. I can paste it.

Let's load this. And, hey, we got our program back.

Okay? So, if I lose my program, say, we go back

to CodeSkulptor it's gone. All right.

Well, it's not really gone, okay? I can paste this back.

However, that filename was randomly generated.

We don't know what it is. So, only you know what it is.

You need to keep track of it. If you lose it, it's gone.

All right? So, how can I keep track of it?

Well, there are several ways. Okay.

One, you could bookmark it. Two, you could look in the history of

your browser. Three, you could copy it and save it into

a file on your computer. Four, you could email it to yourself.

And I'm sure there are many other ways that you could come up with to keep track

of your filenames. All right?

So, you should do whatever you find most comfortable but you absolutely need to

save these filenames. Okay?

And I'm going to show you on Chrome, there's this little star button over

here. I can push that and it will put a

bookmark. So, I'm going to call it hello program.

I'm going to put it in the bookmarks bar, say done.

And here it the/g, here it is. It shows up on the bookmarks bar.

If you don't have a bookmarks bar, you should go through the menus, I'm sure you

can find it. Okay?

And when I push this and it doesn't matter where I am.

Let's open up a new tab. I push this and all of a sudden my

program comes back. Okay?

So, it is critically important that you keep track of these URL's, so that you

can get your files back. I don't want to go through all the

possible ways that you can manage your bookmarks.

You can use Google to find out about that.

All right? But make sure that you do so.

Okay. So, you've written your very important

program and you've saved it to the Cloud and we push the, the Save button.

We are very comfortable that our file has been saved but to be really cautious, we

should download it to our local computer as well.

You really want a copy for yourself, not just relying on the Cloud.

Okay? You could lose the URL, you could lose

something else. And downloading, okay, by pushing

Download button right here, gets the file that you most recently saved to the Cloud

and it brings it back to your local computer.

Okay. So, this button is only going to be

active right after you hit the Save button.

Now, your web browser recognizes that this is a Python program, and so it gives

you a warning, Hey, this program could run and harm your computer.

Well, it's a program that you wrote, it's not going to harm your computer, so you

can ignore this and keep it. All right?

We've now downloaded our program. Okay.

We can actually open the Downloads folder and here we go.

You can see that I have two files that I've downloaded in the past.

All right? And I can actually open them and you can

look at it in Notepad and here is my program.

So, now I have some extra security. And we strongly recommend that after you

get a working program or after you're done working in a particular session,

that you both bookmark the file and you download it to your local machine.

Now, saving your files is only useful if you can actually get them back.

So, if you copy the URL, either into your own file or just copied it, you can paste

it back into the address bar and get your file back.

If you bookmarked your URL, then you can get it back, by using the bookmarks.

Okay? If you forgot to bookmark, you can

actually use your History in Chrome. That's Ctrl+H.

And you can see all these exciting Codes-, CodeSkulptor files I've worked

on. Right.

You push this. You can get something back.

hey that's not the one I wanted. I can keep searching.

Hey, here's another one okay. Okay.

And you can probably find pretty much everything you've done in your History,

all right? Now, what if I downloaded the file

locally? Okay, so here I am at CodeSkulptor, and I

had previously downloaded my file. That's where this Open Local button

comes. If I use the open button, I can navigate

through my hard drive. I can find the file that I care about.

And I can open it, and here it is. Okay?

So, you can use one of these mechanisms to retrieve the files that you've saved,

depending on how you decided to actually save it.

Now, it's never going to be the case that you type your program in one shot, you're

done, you save it, and you submit it, okay?

Programming is an incremental process. So, here I wrote my program, I said,

print hello. I said, oh wait, I was trying to write,

hello world. Okay.

I'm on, hey much better. I Save that.

wait a minute. I like exclamation points.

There's not enough of them. All right, let's Save that.

Oh, wait. Let me run that again.

No, that's not really what I wanted. I wanted this.

Okay? And you keep going,okay?

Eventually, you get to something that you're happy with.

You say, okay, this is the program I want.

You go off and submit it or whatever, okay?

I want you to notice, though, while you're doing that, if you keep saving,

that the name of your file basically stays the same, except this version

number at the end, increments. It started out at zero, then it went to

one, two, three, four, and this is somewhat convenient.

You can actually go back in time while you're working in a session, you keep

saving. You say, oh, I screwed up and I overwrote

things. You can just, even if you didn't bookmark

them, you can change that number and say, oh, I really meant to use that program

one back. And hey, it goes back to my program with

all the exclamation points. Okay, so the version number you might

find that relatively convenient way of going back in time and looking at

previous versions while you've been sitting there working.

Okay, as you can see, I've been working hard on my hello world program here.

And I finally got it the way I want it and I'm ready to submit it to Coursera,

to send it to all my friends and family, and basically show off my, that coolness

of all of my work, all right? You can just use the URL that you have

here and that's perfectly fine. But you'll notice hey, this is the lucky

number 13 version of my, my file and maybe I don't want people to be able to

look back through the history, and see what happened in version number 6, okay?

So, we added a little suitcase button. When you push the suitcase button, it

generates a new filename for you. So, it does everything that the save

button does, it just doesn't have a version number.

Now, if you'd like, you can use this to submit to Coursera, you can use this to

send to your friends and family and they can't see all the versions.

There's nothing wrong with the version numbers, this is just your choice.

There's one final thing I want to call you attention to.

And that is the prefix of the filename right here, okay?

Now, you can see that it's user1 here, but if you go to CodeSkulptor right now

and save, I guarantee you that it's not going to be user1.

So, you guys are going to generate hundreds of thousands of files a week and

this prefix helps us keep those files manageable, all right?

So, we change this every once in a while. We will change it in time, at times that

are not so disruptive, but do be aware that that could change, okay?

And if it changes your version numbers will just keep incrementing.

So, you, here I have User 1, Version 3. If I hit Save and we had changed that to

User 2, it would go to User 2 Version 4, okay?

Another thing I want to call your attention to is the dashes in the

filename. They might be dashes, they might

underbars, okay. Don't worry about that, that's not a big

deal. So, we've now shown you that using

CodeSkulptor, you can save your files to the cloud, and then you can download them

back to your local hard drive. You need to do this early and often,

okay? As you're working, make sure that you

save, all right? And when you're done working, either

because you finished your program or you're tired of working at the computer

for now and you're going to walk away, make sure at that point you bookmark and

you download the file to your local computer.

This will make sure that you can always get it back.

Remember, we cannot recover those URLs for you.

If you lose the URL, we don't know it's yours, we can't find it, we can't get it

back. If you keep the URL, however, you can get

it back. And you can use that URL to submit it to

Coursera. You can use that URL to send to your

friends. Marvel at the wonderful work that you've

been doing in this class and generally enjoy yourself.

Okay? We promise that we will save all these

files in the Cloud throughout the class. All right?

But it's your responsibility to track the URL's.

With that, I hope you have a lot of fun in this class.

Saving in CodeSkulptor

An Introduction to Interactive Programming in Python (Part 1)

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