Data Types

Quick reference

• 00:04 In this video, I want to talk about data types.
• 00:07 Python has a bunch of different data types.
• 00:08 We're going to be looking at five main data types, strings,
• 00:11 numbers, lists, tuples and dictionaries.
• 00:14 And we've already kind of looked at a couple of these strings and numbers.
• 00:17 So, what are data types?
• 00:19 Well, we've got our variable first_name = "John", and John is a string,
• 00:24 what kind of data is this?
• 00:25 It's a string, that's the type of data, data type.
• 00:29 So we already know about strings, strings can have single quotes or
• 00:32 double quotes and we'll get into that a little bit later.
• 00:35 In this video I'm going to give a very,
• 00:37 very quick overview of each of these five things.
• 00:39 We're going to get into them in greater detail later on and
• 00:42 really learn about them much further.
• 00:44 For this video, I just want you to sort of become aware that these are the main data
• 00:48 types that you're going to deal with with Python.
• 00:50 Like I said, Python has a bunch of other data types, but these are the main ones,
• 00:53 they're going to get you like 90% of the way to whatever you ever want to do.
• 00:56 And so that's what we're going to look at.
• 00:58 So we have strings, you could also have a number 41,
• 01:00 and notice the number isn't wrapped in a quotation marks.
• 01:05 If you did wrap this in a quotation mark, it's no longer a number.
• 01:08 Now it's a string, because strings are wrapped in quotation marks.
• 01:11 So like I said, we're going to get into these in more detail later on.
• 01:14 The next one is a list, and a list is an array.
• 01:17 Basically, in any other programming language, we call them arrays, but
• 01:20 Python calls them lists.
• 01:22 They're just lists of things.
• 01:23 And to create one, you use these square brackets and you just go ["John"],
• 01:28 you separate the items in your list with commas.
• 01:34 So John, Tim, and Mary and we can access this just like with a variable.
• 01:40 Print this, we get John, Tim, and Mary.
• 01:42 We can pick out a certain item from our list using these brackets,
• 01:46 now lists start out with zero, this is the zeroth item, this is the first item and
• 01:51 this is second item.
• 01:52 So if we wanted to print out John,
• 01:53 we would print out it's index number which is zero, save this and run it, boom, John.
• 01:58 So those are lists, you can change them, you can add things to them,
• 02:01 you can remove things.
• 02:03 They are what we call mutable and they're ordered from zero, up zero, one, two,
• 02:07 three, four, five, whatever, however many you have, so those are lists.
• 02:11 The next thing is a tuple, and a tuple is just like a list.
• 02:14 It looks exactly like a list.
• 02:15 The only difference is, at least in the way it looks,
• 02:18 is instead of the square brackets, you use these parentheses.
• 02:21 So now it's no longer a list.
• 02:23 Now this is a tuple.
• 02:24 And it's kind of a weird name, tuple, right?
• 02:26 But the thing about tuples is you can't change them.
• 02:29 So with lists, you can add things and remove things, and do all kinds of stuff.
• 02:32 With tuples, once you create them, they're created.
• 02:34 You can't do anything else.
• 02:36 And you can access them in the exact same way as a list.
• 02:40 So boom, we get John if we change this to 1,
• 02:43 we get Tim, have we removed it completely.
• 02:46 It'll print out with the parenthesis, so you know it's a tuple.
• 02:49 So, those are tuples, lists and tuples, very similar.
• 02:52 The last one we're going to look at is a dictionary.
• 02:54 And a dictionary is what we call a hash in most other programming languages,
• 02:59 Python calls them a dictionary.
• 03:00 And they are also a collection of items, but they are unordered.
• 03:04 Where a list and a tuple are ordered, zero, one, two,
• 03:07 three, a dictionary is not ordered.
• 03:09 It's ordered by something called a key and a value pair.
• 03:12 And so to create one of these, let's rename this fav_pizza.
• 03:18 And we use these, instead of the square brackets we use these curly brackets, right?
• 03:23 And you often put them on multiple lines.
• 03:25 So like I said, key value pair, you start out with your key and
• 03:29 let's call this John and use a colon and then the value, and John likes
• 03:34 pepperoni pizza and you separate each item with a comma just like a list and a tuple.
• 03:39 So now we have Tim.
• 03:42 Tim likes "Mushroom" and you can put all these on one line, but
• 03:46 we break them apart into two lines just because it's easier to read.
• 03:49 Mary, likes "Cheese".
• 03:53 And that's it.
• 03:53 So, to access these fav_pizza, we can print out the whole thing
• 03:58 just like with a list and a tuple, we get this thing.
• 04:02 If we want a specific item, same thing, we use the square brackets which doesn't make
• 04:05 a lot of sense, you would think you would use curly brackets, but no, square.
• 04:09 And instead of calling a number like you would with a list or
• 04:12 a tuple, you call the key.
• 04:13 So the first item is a key, the second item is a value.
• 04:16 Key, value.
• 04:18 Key, value, key, value.
• 04:19 So if you want to know what Tim likes on his pizza, you just type in Tim.
• 04:23 So you don't have to know which number it is, you just know the key is Tim.
• 04:27 We save this, run it, boom, mushroom.
• 04:29 want to know what John likes?
• 04:31 Type in John, boom, pepperoni.
• 04:33 So those are the five main data types that you're going to run across most often
• 04:38 in Python.
• 04:39 Like I said, there's some other ones, but they're sort of obscure and
• 04:41 we don't need to learn them at this point in the game.
• 04:43 Strings, numbers, lists. tuples and dictionaries.
• 04:46 Like I said, in the next few videos, we're going to dive into each of these in
• 04:49 more detail, learn how to do things with them, and learn more about them.
• 04:52 So in the next video we're going to jump in and
• 04:57 look at the first one which is strings.

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