Would you like to inspect the original subtitles? These are the user uploaded subtitles that are being translated: 1 00:00:00,709 --> 00:00:08,580 Hey, hello! Let's look at dictionaries in this lecture. This far we've looked at strings 3 00:00:08,580 --> 00:00:15,150 we've looked at lists and tuples and now we have yet another data type and these are 5 00:00:15,150 --> 00:00:23,430 dictionaries. Let me open the python shell. And let me create a list first I'm just 7 00:00:23,430 --> 00:00:28,140 creating this for reference, so to compare lists with dictionaries, but you 9 00:00:28,140 --> 00:00:32,940 don't need to create a list for creating a dictionary. So to create a dictionary 11 00:00:32,940 --> 00:00:40,140 you need curly brackets, so open and closing curly brackets and then inside 13 00:00:40,140 --> 00:00:45,719 that you'd pass the items of the dictionary. Now the difference here with 15 00:00:45,719 --> 00:00:52,230 dictionaries is that instead of letting Python add default indexes for your 17 00:00:52,230 --> 00:01:00,390 items you want to create those indexes yourself exclusively so therefore for 19 00:01:00,390 --> 00:01:09,960 dictionaries you do something like this. Name, a column and then the item. Let me 21 00:01:09,960 --> 00:01:20,159 write another one, surname column and then the other item and yeah that's it. 23 00:01:20,159 --> 00:01:25,950 That's the dictionary. So what we have here is when I was talking about 25 00:01:25,950 --> 00:01:31,229 indexing I was referring to these things. Actually these two are referred to as 27 00:01:31,229 --> 00:01:38,189 keys, not indexes so for dictionaries you can create custom indexes so to say and 29 00:01:38,189 --> 00:01:45,329 so these are keys so we have key and value, key and value. This is good because 31 00:01:45,329 --> 00:01:51,329 now if you want to access one of the values of the dictionary again you'd use 33 00:01:51,329 --> 00:01:56,939 square brackets just as you did with strings lists and tuples and then there you 35 00:01:56,939 --> 00:02:02,909 pass the key which value you want to extract, so if you want to extract John, 37 00:02:02,909 --> 00:02:09,300 you want to pass the key of John and that will extract the John value. Something 39 00:02:09,300 --> 00:02:13,470 to note is that dictionaries are an unordered colecton 41 00:02:13,470 --> 00:02:20,250 of items and so sometimes you may notice that the order of the key and 43 00:02:20,250 --> 00:02:26,550 values is not maintained so you may see that surname has gone to the first place, so 45 00:02:26,550 --> 00:02:32,160 surname Smith and the pair has gone the first one and name John is the second 47 00:02:32,160 --> 00:02:37,110 one and so on. So this is different from lists, strings and tuples. The reason why 49 00:02:37,110 --> 00:02:42,210 Python doesn't keep the order is that you know the way you access dictionaries 51 00:02:42,210 --> 00:02:49,890 is you exclusively pass the key of the dictionary when you access it and so you 53 00:02:49,890 --> 00:02:54,209 don't need to know the order of the dictionary. And whenever you want to access 55 00:02:54,209 --> 00:02:57,510 something you say the surname for instance and that will the return Smith 57 00:02:57,510 --> 00:03:02,340 no matter where Smith is, so whether it is the first one, the second one or over 59 00:03:02,340 --> 00:03:10,500 and so on. And interestingly in dictionaries you can also pass, you can 61 00:03:10,500 --> 00:03:17,940 have like lists as values or even tuples, so let me write a circle there or let me 63 00:03:17,940 --> 00:03:27,000 keep it like that and let me add another key and pair here. Let's say cities. Let's say 65 00:03:27,000 --> 00:03:42,750 Joe Smith lives in three cities, Porto and San Diego and Bali. You close 67 00:03:42,750 --> 00:03:49,769 bracket there so as you see we have the key here, we have a column and then you 69 00:03:49,769 --> 00:03:54,030 have the value which can be anything so it can be string, it can be a number, it 71 00:03:54,030 --> 00:04:01,100 can be at list, a tuple. In this case that's a tuple so if you access now 73 00:04:01,100 --> 00:04:10,070 cities like that, you'd get… Sorry, I'll add two bracket there, so you'd get the tuple. 75 00:04:10,070 --> 00:04:15,959 And then you can also do tricks like you know if you want to access Bali you'd 77 00:04:15,959 --> 00:04:23,789 have other brackets there and pass 2. And that would return Bali, so why is that? 79 00:04:23,789 --> 00:04:27,710 That's because you know up to here you have a tuple, 81 00:04:27,710 --> 00:04:35,849 but that's a triple object and then from that tuple you use again the 83 00:04:35,849 --> 00:04:40,560 square brackets notation to access an item from that tuple, so you want item 85 00:04:40,560 --> 00:04:47,759 with index two and that is Bali and yeah that's about dictionaries. Try them out 87 00:04:47,759 --> 00:04:55,110 some more, play around and you will be able to comfortably create and access items 89 00:04:55,110 --> 00:05:01,099 from a dictionary. So I hope you enjoyed this and talk to you later. 5486