WEBVTT 00:00.120 --> 00:01.280 Welcome back. 00:01.320 --> 00:08.040 In this video we're going to learn about dictionaries and dictionaries stores data in key value format 00:08.040 --> 00:12.360 perfect for structured data like user info settings or configurations. 00:12.520 --> 00:14.400 Think of it like a real dictionary. 00:14.440 --> 00:19.040 You look up a word key to find its meaning, which is the value. 00:19.360 --> 00:25.360 Dictionary is a collection which is ordered, changeable and do not allow duplicates. 00:25.400 --> 00:29.760 Dictionaries are written with curly brackets. 00:29.920 --> 00:32.360 The and have keys and values. 00:32.640 --> 00:39.000 So here, in order to create the dictionary, I specified a new variable called person. 00:39.000 --> 00:40.080 This is the dictionary. 00:40.080 --> 00:45.360 It's of type dictionary equals sign the curly brackets. 00:45.520 --> 00:52.320 And here we need to specify the key value pairs separated with commas. 00:52.680 --> 00:56.960 So the first key value pair is name Alice. 00:57.080 --> 00:58.520 The name is key. 00:58.720 --> 01:00.160 The value is Alice. 01:00.160 --> 01:04.880 And the key value pairs are separated with colon okay. 01:05.360 --> 01:11.000 The second key value pair is h and the value is 30. 01:11.040 --> 01:15.450 The third key is job and the value is engineer. 01:15.490 --> 01:21.490 Dictionaries are written with curly brackets and have keys and values. 01:21.730 --> 01:26.690 Dictionary items are ordered, changeable and do not allow duplicates. 01:26.730 --> 01:35.050 Dictionary items are presented in key value pairs and can be referred to by using the key name. 01:35.050 --> 01:45.170 So in order to access, for example, the age the value of age, we need to specify the dictionary name 01:45.330 --> 01:49.410 followed inside the angled bracket. 01:49.410 --> 01:52.930 The key age run the application. 01:53.170 --> 02:00.490 We get Alice, the value of the name, the age 30 and the job engineer. 02:00.650 --> 02:07.290 Those are the values for those corresponding and respective keys. 02:07.330 --> 02:11.610 Dictionaries can't have two items with the same key. 02:11.810 --> 02:19.370 So here I can't create age like this and making it 40 for example. 02:19.410 --> 02:21.770 Okay, it will give me an error. 02:21.810 --> 02:22.810 Let me run. 02:23.090 --> 02:28.650 And here the duplicate values will overwrite existing values. 02:28.650 --> 02:32.530 So here we have an error because the age is 30 and age is 40. 02:32.730 --> 02:36.130 This will override this age. 02:36.490 --> 02:37.010 Okay. 02:37.210 --> 02:42.130 So this is a big problem when doing large scale applications. 02:42.290 --> 02:47.370 You can add, modify or remove items from dictionaries. 02:47.450 --> 02:52.050 For example I need to modify the job title. 02:52.050 --> 03:01.770 So similar to the list, I can access the job key from the person's dictionary and specify the new value 03:01.770 --> 03:03.490 of it, which is developer. 03:03.650 --> 03:12.010 Now we can add a new key value pair, which is the city to the person dictionary, which is Boston. 03:12.170 --> 03:14.810 Let me run again and here we go. 03:14.970 --> 03:19.970 Name Alice, age 40, job developer and city Boston. 03:20.010 --> 03:22.330 Also we can remove the key. 03:22.450 --> 03:27.050 So here I am using delete person age. 03:27.210 --> 03:31.410 I am deleting the age key value pair. 03:31.450 --> 03:35.620 If we print it again name job and city. 03:35.660 --> 03:37.380 We don't have age. 03:37.580 --> 03:47.660 Okay, so this is how we control and, um, add remove items and key value pairs from dictionaries. 03:47.700 --> 03:56.620 Also, there is a very important note here how to loop through a dictionary for key value in person 03:56.620 --> 04:00.780 dot items you are accessing person which is the dictionary. 04:00.820 --> 04:07.660 Using the items function, go and create key and value. 04:07.820 --> 04:09.780 Let me run and here we go. 04:10.140 --> 04:11.340 Key name. 04:11.380 --> 04:12.460 Value Alice. 04:12.500 --> 04:13.980 Key job value. 04:13.980 --> 04:14.900 Developer. 04:14.940 --> 04:16.900 Key city value. 04:17.140 --> 04:23.220 Boston okay, this is the updated version of, uh, person dictionary okay. 04:23.260 --> 04:25.620 Because we deleted the age. 04:25.660 --> 04:26.740 Did you remember. 04:26.740 --> 04:31.220 So here we have those three keys and values okay. 04:31.420 --> 04:34.380 So this is how we loop through a dictionary. 04:34.580 --> 04:36.300 This is how we remove a key. 04:36.580 --> 04:41.740 This is how we add and modify the value of items. 04:41.740 --> 04:46.900 And this is how we create dictionaries and access the values using the keys.