WEBVTT 00:00.110 --> 00:06.740 This is the solution for the activity nine where we will start from this blink LED code. 00:06.740 --> 00:08.570 We're going to create a new Python file. 00:08.570 --> 00:10.310 From that we're going to execute it. 00:10.340 --> 00:13.520 Notice the difference between Tony and the terminal. 00:13.520 --> 00:16.820 And then improve the code with a try except block. 00:16.820 --> 00:19.640 So let's start with the first step. 00:19.640 --> 00:22.040 I already have the code here to make the LED blink. 00:22.040 --> 00:29.570 What I will do is I will use the command CP to copy the LED dot pi into activity. 00:29.570 --> 00:32.570 So for pi I could use the Autocompletion here. 00:32.570 --> 00:35.000 I can't because it's a new file name. 00:35.000 --> 00:38.660 So activity let's call it nine dot pi. 00:39.380 --> 00:47.420 Okay so I have my activity nine dot pi that contains activity nine that contains the same contents. 00:47.450 --> 00:48.350 No surprise. 00:48.350 --> 01:01.880 And I'm going to now go to step two okay I'm going to open this from Sony Open Activity nine okay. 01:02.960 --> 01:09.170 And just to make sure that we have enough time to stop the program, I'm just going to put a two seconds 01:09.170 --> 01:09.740 here. 01:10.940 --> 01:11.090 Okay. 01:11.090 --> 01:15.500 So the LED will be on for two seconds and then off for one second. 01:15.530 --> 01:18.680 So we have more time to stop the program and see what happens. 01:18.680 --> 01:22.400 This is specifically in this part that I want to make experiments here. 01:22.400 --> 01:24.800 So let's run the program. 01:26.150 --> 01:30.590 And as expected it's on for two seconds off for one second. 01:30.650 --> 01:38.690 Now if I stop it, you see, if I stop it here when the LED here is still on, then the LED stays on, 01:38.690 --> 01:41.990 which means that the Gpio was not correctly cleaned up. 01:41.990 --> 01:50.780 Now let's go to the terminal and let's run Python three activity nine okay. 01:51.080 --> 01:51.860 So what. 01:51.860 --> 01:54.860 It's going to do the same thing on and then off. 01:56.150 --> 01:58.520 And I'm going to do control C here. 01:58.640 --> 02:00.290 Actually I think it was off. 02:00.290 --> 02:04.490 So I'm going to try again on off and then on. 02:04.490 --> 02:05.450 And I press Ctrl C. 02:05.480 --> 02:10.220 And you can see right now here that the LED was turned off okay. 02:10.250 --> 02:12.320 So this is the same case as before. 02:12.320 --> 02:18.530 We were in the part of the code where the LED was turned on, and then we were waiting for two seconds. 02:18.530 --> 02:22.190 But when I stopped it from this button here, it stayed on. 02:22.190 --> 02:27.230 Which means that as I told you, the Gpio was not correctly cleaned up here from the terminal, and 02:27.230 --> 02:33.500 probably if you also run it from the shell here when I stop the program with control C, even if the 02:33.500 --> 02:39.920 LED is on, you can see that, then the LED is going to be turned off, which means that the Gpio was 02:39.920 --> 02:40.790 cleaned up. 02:40.820 --> 02:41.090 Okay. 02:41.120 --> 02:43.610 So as you can see we will try. 02:43.640 --> 02:47.930 Not later on we will try not to run the code. 02:47.960 --> 02:55.820 So any code that uses Gpio using display and the stop button here we will try to run it either maybe 02:55.850 --> 02:59.720 in a shell or in the terminal which might work better. 02:59.720 --> 03:02.660 And now I'm going to go to the last part of this activity. 03:02.660 --> 03:07.880 So you can see when we do control C we have an exception here and a keyboard interrupt. 03:07.880 --> 03:11.270 So let's try to exit in a smooth way. 03:11.270 --> 03:13.910 So I'm going to write the code here directly from Thonny. 03:13.940 --> 03:16.220 Since the program is open here. 03:16.340 --> 03:18.080 And I'm going to do a try. 03:18.110 --> 03:21.600 And I'm going to put all that inside the to try. 03:22.890 --> 03:23.160 Okay. 03:23.190 --> 03:26.730 And after this, I go back to the same indentation as the try. 03:26.730 --> 03:33.420 And I do accept keyboard interrupt with a colon. 03:33.420 --> 03:36.090 I go back to a new line and do I want to do something? 03:36.120 --> 03:38.700 Well, if you want to do something, you can do it. 03:38.700 --> 03:40.650 You can write something with a print. 03:40.680 --> 03:42.060 Run some other comments here. 03:42.060 --> 03:43.500 I'm just going to do pass. 03:43.500 --> 03:46.080 So I'm going to save that. 03:46.140 --> 03:49.530 You can note it's important if you're going to run the script from the terminal. 03:49.530 --> 03:55.800 It's important that first you save from Tony here, because in Tony, when you run the script, anytime 03:55.800 --> 03:57.870 you run the script, it's going to save it anyway. 03:57.870 --> 03:59.010 So save and run. 03:59.010 --> 04:02.250 But from the terminal, it's not going to save the file for you. 04:02.250 --> 04:08.610 So you need to make sure that you save with Ctrl S or also file and save here. 04:08.610 --> 04:12.510 So now that this file is saved, let's run it again. 04:12.510 --> 04:15.360 And then I'm just going to press Ctrl C whenever. 04:15.360 --> 04:18.630 And you can see now we don't have this message here. 04:18.660 --> 04:21.000 This exception message. 04:21.270 --> 04:21.720 Great. 04:21.720 --> 04:23.490 And that's the end of this activity. 04:23.490 --> 04:28.470 And as you can see now you can do quite a lot of things with Python and the terminal.