#100DaysOfWeb in Python Transcripts
Chapter: Days 9-12: FastAPI
Lecture: Know your HTTP verbs
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You can see that working with HTTP verbs, get, post, put, and so on, all of those things
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are right up in front when we work with building APIs with FastAPI.
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And understanding what verbs are out there and when they should be used is really important when you're building RESTful APIs.
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So let's just take a moment and talk about the four most common HTTP verbs. There are others that we're not going to mention here.
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You can go look at this link at the bottom to see them all. The one that everyone who has interacted with a computer on the web is familiar with is
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get. So get is just give me the information on this resource. Like any time you're using a browser, most things you're doing are just click a link,
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do a get. So the get requests a representation of a specified resource, in our case the result
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of that calculation, and it should only be used to retrieve data.
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One of the really important ideas around get is that it's supposed to be potentially cacheable,
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whether or not you access it multiple times or whatever. It shouldn't change the state of the system.
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There was a really interesting bug in Wikipedia way, way, way back in the early days when
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there was a delete button, actually had a just a get request to delete a resource.
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And then the web spiders like Google went through and started trying to index Wikipedia
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and started following those links and started deleting the pages. So yeah, don't do that kind of stuff. Get to just return things.
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Think of get as read only. If you want to change something, if you want to modify something, use HTTP post.
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This is to submit some new object, some new data, which is going to cause a change in the server potentially.
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So if you're going to log in, you're going to create an account, you might submit your
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username and your password that you want to create the account with. And of course, the state that's being changed on the server as well.
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Now there's a new account with that username and password that you can log in.
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Delete similar to post in that it modifies things, but if I want to remove a resource,
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so if I had like a bookstore and I had slash books slash book seven, and we decide, you know, we don't want book seven anymore.
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And the API could set it up. So I do a delete request against that URL against book slash seven, and the server could
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respond by deleting book seven, no longer there. Also similar to post is we have put now with post you say I have some data, I want you
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to create it on the server. Basically what comes back is great, I recreated this and here is where it lives.
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But if you already know where you want it to be in terms of the URL, think of like a
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blog post, blog posts, you might already know the URL where you want your blog post to live,
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but it doesn't yet exist, you could do an HTTP put and say, I would like to make this location have this blog post, right?
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You don't let the server control where the thing gets created. You you say explicitly server put it here.
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This is not nearly as common as post but sometimes you'll see it used in these are the four most
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common HTTP verbs as far as writing APIs and you know, explicitly making them part of your API.
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There are a bunch of others like I said at the bottom you can check out but get for read
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only posts for making changes, delete to delete put if you know where it's going.