1 00:00:00,380 --> 00:00:01,239 [MUSIC] 2 00:00:01,239 --> 00:00:06,119 Welcome to Introducing Dictionaries, 3 00:00:06,119 --> 00:00:14,150 I'm Ashley Boucher and I'll be your teacher for this course. 4 00:00:14,150 --> 00:00:16,777 Before moving forward, take a second to check the teacher's notes and 5 00:00:16,777 --> 00:00:19,730 make sure you've completed all of the prerequisites for this course. 6 00:00:19,730 --> 00:00:23,260 Remember, any questions you have can be asked in the Treehouse community. 7 00:00:23,260 --> 00:00:25,963 The community is also a great place to help other students and 8 00:00:25,963 --> 00:00:27,447 answer their questions as well. 9 00:00:27,447 --> 00:00:29,136 Ready to get started? 10 00:00:29,136 --> 00:00:32,628 In this course you're going to learn about a new type of Python data structure, 11 00:00:32,628 --> 00:00:33,980 the dictionary. 12 00:00:33,980 --> 00:00:36,646 A dictionary is a set of key value pairs. 13 00:00:36,646 --> 00:00:41,049 Think of a Python list, an ordered sequence of comma separated values, 14 00:00:41,049 --> 00:00:42,910 indexed by numbers. 15 00:00:42,910 --> 00:00:45,760 A dictionary does have similarities to a list. 16 00:00:45,760 --> 00:00:49,220 For instance, dictionaries also contain comma separated values, 17 00:00:49,220 --> 00:00:51,910 but that's really where the similarities end. 18 00:00:51,910 --> 00:00:55,830 In a dictionary, each of its values has a label called the key. 19 00:00:55,830 --> 00:00:58,320 And dictionaries are not sequences, they aren't ordered. 20 00:00:58,320 --> 00:01:02,160 They're indexed by their keys, not numbers. 21 00:01:02,160 --> 00:01:05,660 You'll see variations of dictionaries in just about every programming language. 22 00:01:05,660 --> 00:01:09,115 You might know them as associative arrays or associative memories. 23 00:01:09,115 --> 00:01:12,373 They're the earliest stepping stone in thinking about object 24 00:01:12,373 --> 00:01:13,665 oriented programming, 25 00:01:13,665 --> 00:01:18,790 a design pattern that revolves around modeling reusable objects in your code. 26 00:01:18,790 --> 00:01:20,120 It's an exciting topic, 27 00:01:20,120 --> 00:01:23,400 join me in the next video to start learning more about key value pairs.