WEBVTT 00:00.080 --> 00:00.920 Welcome back. 00:00.960 --> 00:03.680 We finished the predict mileage function. 00:03.720 --> 00:09.960 Now let's create another function that validates the features range. 00:10.200 --> 00:16.720 Think about if the user enters number of cylinders like for example 12. 00:16.880 --> 00:25.800 And your data set is programmed and uh and the range is between 3 and 9 cylinders. 00:26.040 --> 00:27.640 This is out of range. 00:27.640 --> 00:30.720 So we need to validate the features. 00:30.720 --> 00:36.120 We need to allow the user to enter uh cylinders between 3 and 8. 00:36.160 --> 00:40.680 Displacement between 68 and 45 455. 00:41.000 --> 00:46.400 Horsepower between 46 and uh, 230, and so on. 00:46.440 --> 00:52.360 Okay, in order to do that, we need to create a new function here. 00:52.480 --> 00:56.920 Let's name it as validate features. 00:56.920 --> 01:04.600 Takes car feature object and returns a validation result object. 01:04.640 --> 01:11.420 This is a data class that we created before called validate results in the car features. 01:11.580 --> 01:19.420 So let me correct the name validate results and Alt plus enter to import this data class. 01:19.460 --> 01:19.940 Okay. 01:20.260 --> 01:29.140 So it takes a car features instance and returns a data class validate results instance. 01:29.180 --> 01:32.940 Okay start with val errors. 01:32.980 --> 01:36.900 Mutable list of strings. 01:36.940 --> 01:38.060 Name it errors. 01:38.060 --> 01:41.380 And let's check every feature. 01:41.380 --> 01:46.300 If there is any error in any feature, it will be added to the errors. 01:46.300 --> 01:47.580 Mutable list. 01:47.620 --> 01:51.140 Okay, so this is the logic behind this. 01:51.420 --> 02:02.340 So if car features dot slender, if it is not in three cylinders to eight cylinders, then go and add 02:02.380 --> 02:04.380 to the errors list. 02:04.540 --> 02:09.930 This line cylinders must be between 3 and eight. 02:10.130 --> 02:12.650 So guys again it's very clear. 02:12.690 --> 02:13.250 Okay. 02:13.290 --> 02:15.250 Car features, not cylinders. 02:15.250 --> 02:19.610 If the added number of cylinders is not between 3 and 8. 02:19.770 --> 02:21.930 Go and add to the errors. 02:21.930 --> 02:23.010 Mutable list. 02:23.290 --> 02:28.370 This line of code cylinders must be between 3 and 8. 02:28.410 --> 02:35.130 Okay, so another check if car features dot displacement. 02:35.170 --> 02:42.650 It's not in 68 F to 455 F. 02:42.850 --> 02:45.290 Then what we need to do errors. 02:45.290 --> 02:51.210 Displacement should be added between 68 and 455. 02:51.250 --> 02:55.090 Okay, let me continue with car features. 02:55.130 --> 02:56.730 The horsepower. 02:56.770 --> 02:58.530 This is for horsepower. 02:58.810 --> 03:02.130 The weight between this number. 03:02.330 --> 03:04.970 Then errors must be added. 03:04.970 --> 03:07.090 The weight acceleration. 03:07.130 --> 03:15.830 If it is not in eight f, 25 F, if not the model year, it's not between 70 and 82. 03:15.870 --> 03:17.670 The model year between 82. 03:17.910 --> 03:18.390 Okay. 03:18.630 --> 03:21.110 This is the validation. 03:21.150 --> 03:24.230 This is the validation result. 03:24.430 --> 03:24.870 Okay. 03:25.190 --> 03:29.150 Now we need to return a validation result object. 03:29.310 --> 03:31.710 Having this valid errors is empty. 03:31.710 --> 03:32.550 And errors. 03:32.590 --> 03:37.910 Errors if it is not are not having any errors. 03:37.950 --> 03:41.070 Go and set the valid to true. 03:41.230 --> 03:44.790 So I'm checking if errors list is is empty. 03:45.070 --> 03:50.950 So if this errors list is empty go and return is valid true. 03:50.990 --> 03:53.790 Otherwise go and return the errors. 03:53.830 --> 03:57.430 Okay, this is the idea behind this function. 03:57.430 --> 03:59.030 Validate features. 03:59.030 --> 04:09.070 We're going to use it in the next videos in order to ensure that our codes are are, um, are working 04:09.110 --> 04:16.790 fine and we don't enter any, uh, unacceptable and out of range inputs.