WEBVTT 0 00:00.320 --> 00:00.890 Now, 1 00:00.890 --> 00:09.080 hopefully, you've already got everything set up so that you're ready to go on the Day 1 tasks, and you're 2 00:09.080 --> 00:11.780 able to see what I'm seeing right here. 3 00:11.780 --> 00:17.900 Now, if you don't know what I'm talking about, or if you don't have access to any of this, be sure 4 00:17.900 --> 00:24.170 to go back to the previous lesson where I showed you, step-by-step, 'How to Download' and get hold of 5 00:24.170 --> 00:31.980 the latest version of the Curriculum Exercises on PyCharm. So be sure you do that before you proceed, 6 00:31.980 --> 00:38.340 so that we're all starting at the same place and you're seeing exactly what is shown in the videos, 7 00:38.340 --> 00:41.640 and we're ready to start learning how to program. 8 00:41.640 --> 00:47.130 Now, remember that the whole reason why we're learning to program is to be able to tell the computer 9 00:47.130 --> 00:51.240 what it needs to do, and for it to follow our commands. 10 00:51.240 --> 00:54.610 So let's go ahead and tell the computer to do something. 11 00:54.670 --> 00:58.240 And we're going to do that by writing our first line of code. 12 00:58.360 --> 01:04.120 So in this case I'm creating something called a "print function", which is just the word print all in 13 01:04.120 --> 01:07.720 lowercase and then followed by a set of parentheses(). 14 01:07.750 --> 01:13.270 Now inside these parentheses, I'm going to tell it what I want it to print. 15 01:13.270 --> 01:17.830 And hopefully it's going to output that inside our console. 16 01:18.530 --> 01:24.110 So I'm going to start off by writing the classic "Hello world!" inside here, 17 01:24.110 --> 01:28.100 and then once you're ready then go ahead and click Run. 18 01:28.490 --> 01:34.550 After a few seconds you should see the computer follow your command, namely printing the words that 19 01:34.550 --> 01:39.500 you told it to print inside the console or the output area over here. 20 01:39.770 --> 01:47.260 And once it's done, it indicates that by writing, "Process finished with exit code 0", which means 21 01:47.260 --> 01:51.490 everything was successful, everything was run without any issues. 22 01:51.490 --> 01:58.120 Now, just to break down this area a little bit more for you, if you look at the top line here, which 23 01:58.120 --> 02:04.420 you'll always, always see, there's a lot of text in here, but it's actually very simple to understand. 24 02:04.420 --> 02:12.170 Essentially, it's telling you the location of the current file that is being run that has resulted in 25 02:12.170 --> 02:13.190 this output. 26 02:13.190 --> 02:17.210 So in our case, it's the Day 1 task. 27 02:17.210 --> 02:21.380 And you'll see this change as you go through the different days 28 02:21.380 --> 02:26.240 because the location of this file, where you wrote the code, will change. 29 02:26.240 --> 02:31.200 So the first line is the location of the file that you executed. 30 02:31.230 --> 02:38.550 The second line, or multiple lines in between, is the result of your command to the computer. 31 02:38.550 --> 02:45.660 And then finally at the very, very end, it tells you if the process finished with success, which 32 02:45.660 --> 02:51.570 is in this case, or if there are any other issues, it would show up here as well, which we're going 33 02:51.570 --> 02:53.400 to see very, very shortly. 34 02:53.490 --> 03:00.430 And to be sure that you're always running the current file, make sure that this drop down is selected 35 03:00.430 --> 03:01.750 as Current File, 36 03:01.750 --> 03:09.010 and that way, every time you press the play button here, it will run the code into the output area. 37 03:09.580 --> 03:15.640 Now if you want to do a shortcut and you're really into keyboard shortcuts, you can hover over the 38 03:15.640 --> 03:24.560 play button and you'll see the shortcut on what I'm using, which is a Mac, is Control + R, in Windows 39 03:24.560 --> 03:25.250 or Linux, 40 03:25.250 --> 03:30.290 it'll show up different shortcuts, but it should all show up there if you want to try that out. 41 03:30.290 --> 03:34.370 Alternatively, just keep pressing the play button and it works just as well. 42 03:34.520 --> 03:37.490 And the way that this command works is super simple. 43 03:37.490 --> 03:44.220 You have the keyword, "print", followed by a set of parentheses, and then inside the parentheses, you 44 03:44.220 --> 03:46.320 tell it what you want it to print. 45 03:46.500 --> 03:52.890 And once you've inserted that, then when this line of code gets executed by the computer, it'll know 46 03:52.890 --> 03:58.110 to simply print or output the thing that you've placed in between the parentheses. 47 03:59.310 --> 04:07.230 But notice here that it's not just the word, "Hello world!", that I've put inside my parentheses, 48 04:07.300 --> 04:12.970 I've also added some quotation marks or double quotes around the word, 49 04:13.090 --> 04:20.530 and the reason why I've done this is so that I can tell the computer that this bit here, in between 50 04:20.530 --> 04:22.840 the double quotes, is not code. 51 04:22.840 --> 04:25.990 It's not like print where it's supposed to do something, 52 04:25.990 --> 04:30.190 this is just some text that I've made up, that I want it to print out. 53 04:31.180 --> 04:36.320 And these pieces of text in programming lingo, is known as "Strings". 54 04:36.320 --> 04:40.070 And you can imagine it as almost like a pearl necklace. 55 04:40.070 --> 04:40.370 Right? 56 04:40.370 --> 04:43.310 It's a string of characters. 57 04:43.490 --> 04:52.970 And what the double quotes do, is they basically show the beginning and the end of that string of characters. 58 04:53.810 --> 04:57.760 So that means you have to be really careful when you're typing. 59 04:57.760 --> 05:05.260 For example, if I go ahead and I miss out the closing double quote, well, now you can see that there's 60 05:05.260 --> 05:11.350 some changes that have happened to our code already, namely that the last parentheses, instead of 61 05:11.350 --> 05:18.310 being colored in white like the opening parentheses or how it used to be, it's now colored in green, 62 05:18.310 --> 05:23.380 the same color as the rest of our text or our string. 63 05:23.380 --> 05:25.600 And this is a subtle hint to us. 64 05:25.600 --> 05:31.990 You're going to get really attuned to these subtle hints, because they are the clues that will tell 65 05:31.990 --> 05:34.360 you what might have gone wrong in your code. 66 05:34.360 --> 05:38.350 If I run this code as it is right now, it's going to break. 67 05:38.350 --> 05:45.780 It's going to give me a SyntaxError, and it says something that seems like it's completely not English. 68 05:45.780 --> 05:48.840 So how can we figure out what this means? 69 05:49.500 --> 05:54.270 Now, the thing I want you to know is that all programmers make mistakes. 70 05:54.270 --> 06:01.980 We all make lots of errors, like forgetting to add the double quotes at the end of the string, or 71 06:01.980 --> 06:05.730 forgetting to add a closing parentheses. 72 06:05.730 --> 06:09.060 These things are just common errors because we're human. 73 06:09.250 --> 06:15.910 But the thing that differentiates great programmers is we're really good at figuring out what the problem 74 06:15.910 --> 06:17.380 is and how to fix it. 75 06:17.380 --> 06:22.000 So you can imagine that coding is just a whole bunch of problems that you have to solve. 76 06:22.000 --> 06:29.500 And in this case, when we get some sort of red text, and our code is not doing what we expect it to do, 77 06:29.500 --> 06:35.570 then all we have to do is take this entire error message where it says something, something error, 78 06:35.570 --> 06:41.030 and this is some sort of message that we're supposed to understand, and we're simply going to drop 79 06:41.030 --> 06:42.050 it into Google. 80 06:42.050 --> 06:47.480 And usually the first link you come across will be from a website called stackoverflow.com. 81 06:47.480 --> 06:53.510 And this is basically the Q&A website that all developers will go to whenever something is wrong with 82 06:53.510 --> 06:56.360 their code, or when they can't figure out how to do something. 83 06:57.570 --> 07:03.150 So if we click on this link, you can see that somebody else has also had this error, 84 07:03.330 --> 07:10.140 and some kind souls have told us that the solution might be the fact that you're missing a double quote 85 07:10.140 --> 07:12.150 before the end of the line. 86 07:12.150 --> 07:18.330 So if we take a look back at our code, the code that generated this error looks like this. 87 07:18.330 --> 07:23.320 And indeed, we are missing a double quote at the end of our string. 88 07:24.790 --> 07:30.160 As you're learning to code, as you're going through your 100 Days, I want you to become more and more 89 07:30.160 --> 07:37.180 attuned to the color of your code, because one of the most helpful things that code editors such as 90 07:37.180 --> 07:41.800 this do for us is something called, "Syntax highlighting". 91 07:41.890 --> 07:49.130 For example, when I was missing that double quote, it highlighted this entire thing and that is basically 92 07:49.130 --> 07:53.360 it telling us, it seems like this whole thing is some text. 93 07:53.360 --> 07:59.780 It thinks that all of this is a string and that we're missing a closing parenthesis. 94 08:00.800 --> 08:05.510 So if you notice this and you're like, wait, actually that's not right, 95 08:05.510 --> 08:09.800 this part should match the color of the open brace, which is white. 96 08:09.800 --> 08:11.910 So there must be something wrong here. 97 08:11.910 --> 08:18.810 And indeed, if you have a look at the error message, it actually has a little caret sign right here 98 08:18.810 --> 08:23.370 showing you that there's something that's probably not right here. 99 08:23.370 --> 08:29.400 And it might jog your memory that, "Oh yeah, I've forgotten a closing double quote." 100 08:30.510 --> 08:38.050 Now, the really handy thing about PyCharm is it actually underlines your errors before you even run 101 08:38.050 --> 08:38.980 your code. 102 08:38.980 --> 08:46.450 And if you hover over the underline, it usually gives you some intelligent guess as to what your problem 103 08:46.450 --> 08:47.200 might be. 104 08:47.200 --> 08:50.260 And in this case, it's absolutely spot on. 105 08:50.260 --> 08:55.600 It says, you're missing a closing quote, which is exactly what we're missing. 106 08:55.600 --> 09:01.580 So that will also be really helpful for us to figure out what it is that we need to do. 107 09:01.580 --> 09:07.970 But as with all things with AI, if we don't know what we're doing in the first place, these hints 108 09:07.970 --> 09:09.440 don't help us that much. 109 09:09.440 --> 09:15.320 For example, if I put the closing quote right here, I've got other problems and I'm going to create 110 09:15.320 --> 09:16.820 more problems for myself. 111 09:16.820 --> 09:24.330 So it's important that we first understand how things work and then use technology and AI to help us, 112 09:24.330 --> 09:26.880 such as in this case, to fix our bug. 113 09:27.690 --> 09:36.090 Now, you'll notice that there is also a tiny squiggly line under this closing brace, but in this case, 114 09:36.090 --> 09:42.450 it's not in red, so it's not an error, but instead it's in yellow, which is a warning. 115 09:42.480 --> 09:50.300 Now, most of these warnings come from a good standard practice for how to write code. 116 09:50.300 --> 09:57.560 And if we hover over this warning, it tells us that PEP 8, which is guidance for how to write 117 09:57.560 --> 10:04.910 Python code, and it tells you that the problem that it's seeing is there's no new line at the end of 118 10:04.910 --> 10:05.780 the file. 119 10:05.810 --> 10:11.120 Now, we can ignore all of this because it's a bit too complicated, and it's actually very simple to 120 10:11.120 --> 10:12.300 solve this problem. 121 10:12.300 --> 10:18.930 All it's saying is that in good practice, when we're writing Python code, there should be a new line 122 10:18.930 --> 10:25.950 at the end of the file so that we have our cursor down here instead of ending right there. 123 10:25.950 --> 10:27.930 And that's all there is to it. 124 10:27.930 --> 10:31.650 And with that one thing, we've gotten rid of all our errors, 125 10:31.650 --> 10:33.720 we've gotten rid of all our warnings, 126 10:33.720 --> 10:39.220 our code looks good stylistically, as well as syntactically. 127 10:39.220 --> 10:43.750 All these big words that all that it means is that it looks great in every single way. 128 10:43.750 --> 10:49.120 And we've got our little check mark, which means no problems found by the editor. 129 10:49.120 --> 10:54.310 Now, sometimes the editor can be really picky, and some of the things that it tells you, you can safely 130 10:54.310 --> 10:54.760 ignore, 131 10:54.760 --> 10:59.560 but as always, we need to understand how everything works before we can do that. 132 10:59.800 --> 11:05.750 So now that we've embarked on our first step to write some code and start commanding the computer to 133 11:05.750 --> 11:10.730 do what we want it to do, which is to print out some words into the output area, 134 11:10.730 --> 11:13.190 it's now time for a challenge. 135 11:13.190 --> 11:19.040 So head over to the next lesson, and we're going to test you on what you've learned in this lesson 136 11:19.040 --> 11:21.650 by practicing writing some print statements. 137 11:21.650 --> 11:25.340 So for all of that and more, I'll see you on the next lesson.