1 00:00:00,009 --> 00:00:05,510 Welcome to lesson two. And previously, we successfully created 2 00:00:05,739 --> 00:00:10,899 our very first program that printed the words Hello world. 3 00:00:11,189 --> 00:00:15,909 Now, I wanted to use this opportunity to really break this 4 00:00:16,079 --> 00:00:18,010 program down and 5 00:00:18,190 --> 00:00:21,909 help you understand what exactly we did because 6 00:00:22,059 --> 00:00:24,280 I'm going to assume it's your first ever program 7 00:00:24,290 --> 00:00:26,670 and you're new to the world of programming. 8 00:00:27,180 --> 00:00:27,719 So 9 00:00:28,049 --> 00:00:33,669 right here we initiated the command called print. Now, print is a function 10 00:00:34,169 --> 00:00:39,430 with Python. You have inbuilt functions that will do something for you. 11 00:00:39,889 --> 00:00:43,409 Print is one of such functions that will of course print 12 00:00:43,419 --> 00:00:45,799 out whatever it is that we tell it to print. 13 00:00:46,450 --> 00:00:51,029 Now notice that we do have the parentheses, 14 00:00:51,290 --> 00:00:52,810 OK? Opened up. And 15 00:00:53,029 --> 00:00:56,430 typically whenever you're working with functions with Python, 16 00:00:56,639 --> 00:00:58,240 you will have the name of the function. 17 00:00:58,250 --> 00:01:01,790 And then you're gonna have parentheses which are the brackets 18 00:01:02,229 --> 00:01:04,529 and inside of the parentheses, 19 00:01:04,540 --> 00:01:07,750 you're going to have something that we call a variable. 20 00:01:07,760 --> 00:01:08,150 OK? 21 00:01:08,849 --> 00:01:10,500 Variables are kind of like 22 00:01:10,949 --> 00:01:13,269 inputs or data 23 00:01:13,480 --> 00:01:17,150 that we give to the function to work with. 24 00:01:17,550 --> 00:01:18,199 OK. In 25 00:01:18,430 --> 00:01:20,510 this case right now, the 26 00:01:20,669 --> 00:01:24,330 variable is the text. Hello World. 27 00:01:24,650 --> 00:01:27,029 Now we're letting Python know 28 00:01:27,559 --> 00:01:31,300 that Hello world is text. It's a string format. 29 00:01:31,309 --> 00:01:34,709 Don't worry, we're gonna talk a bit more about data types a bit later. 30 00:01:35,150 --> 00:01:40,690 But in order for Python to understand that Hello World is actually a piece of text, 31 00:01:40,989 --> 00:01:45,620 we wrapped it in double quotation marks. As you can see. 32 00:01:45,629 --> 00:01:48,099 That's why Python knows that all 33 00:01:48,239 --> 00:01:52,250 these aren't numbers. This is not some sort of a calculation. 34 00:01:52,430 --> 00:01:55,910 These are just letters or words that need to be printed out. 35 00:01:56,110 --> 00:01:59,160 That's why we wrap them in quotation Mac. 36 00:01:59,620 --> 00:02:04,220 Now, if I was to come over here right now and typed in something, 37 00:02:04,230 --> 00:02:05,709 just something random 38 00:02:05,940 --> 00:02:09,800 notice, it's of course, outside of the quotation marks. 39 00:02:10,139 --> 00:02:10,589 OK. 40 00:02:11,279 --> 00:02:14,600 If I was to go ahead right now and run my program, 41 00:02:14,610 --> 00:02:18,380 you will see right now that it displays an error because 42 00:02:18,699 --> 00:02:21,240 the syntax isn't correct. 43 00:02:21,529 --> 00:02:23,690 If you're going to display anything 44 00:02:23,899 --> 00:02:25,960 using Python and the print function, 45 00:02:26,190 --> 00:02:32,339 it needs to be in quotation mark. So this isn't going to work. Let me go back, 46 00:02:33,559 --> 00:02:34,699 add my 47 00:02:34,889 --> 00:02:36,529 double quotation again, 48 00:02:37,139 --> 00:02:38,039 run 49 00:02:38,520 --> 00:02:40,039 and we're back. OK? 50 00:02:40,770 --> 00:02:46,649 What if I wanted to print? Hello World, let's say five times. OK? 51 00:02:46,839 --> 00:02:49,600 Now I could do this. OK? 52 00:02:49,610 --> 00:02:54,470 I could simply just copy and then come over here, paste, paste, paste, paste. 53 00:02:54,750 --> 00:02:56,860 And then if I was to run, 54 00:02:57,339 --> 00:03:01,309 you can see right now it will print out Hello World five times. 55 00:03:01,320 --> 00:03:02,399 Pretty straightforward. 56 00:03:02,889 --> 00:03:05,559 OK? Let me just go ahead and remove 57 00:03:06,039 --> 00:03:07,679 the four additional lines. 58 00:03:08,710 --> 00:03:10,889 I want to show you a different way. 59 00:03:11,039 --> 00:03:11,729 OK. 60 00:03:12,100 --> 00:03:14,350 We could do something like this. OK? 61 00:03:14,729 --> 00:03:21,039 I am going to create something that I've mentioned before and that's a variable. OK? 62 00:03:21,050 --> 00:03:23,660 Variables. Again, they're like inputs 63 00:03:23,839 --> 00:03:25,929 that we can use to store data. 64 00:03:26,300 --> 00:03:31,610 Now, I'm going to call this variable, let's say text, let's call it text one. 65 00:03:31,970 --> 00:03:32,610 OK? 66 00:03:33,020 --> 00:03:36,600 That's the name of my variable. And I'm gonna say it's equal to 67 00:03:36,970 --> 00:03:39,070 and now in double quotation marks. 68 00:03:39,710 --> 00:03:40,839 Hello 69 00:03:41,630 --> 00:03:42,529 world. 70 00:03:42,850 --> 00:03:43,369 OK. 71 00:03:43,710 --> 00:03:46,699 So what I've done right now is I have simply said, 72 00:03:47,000 --> 00:03:51,990 I'm going to add the text. Hello World to the variable text one. 73 00:03:52,000 --> 00:03:57,940 So text one, the variable text one is now holding it has the value of hello world. 74 00:03:57,949 --> 00:03:59,179 Now check this out. OK? 75 00:03:59,449 --> 00:04:02,330 I'm gonna go over here right now to my print function, 76 00:04:03,130 --> 00:04:04,679 remove 77 00:04:04,940 --> 00:04:06,410 the text, the string 78 00:04:06,830 --> 00:04:09,380 and I'm simply gonna say text 79 00:04:09,490 --> 00:04:10,399 one 80 00:04:11,809 --> 00:04:16,250 because again, text one is equal to hello world. 81 00:04:16,540 --> 00:04:17,269 And now 82 00:04:17,459 --> 00:04:19,029 I'm going to run my command 83 00:04:19,420 --> 00:04:22,769 and here it is we have Hello world. 84 00:04:22,899 --> 00:04:27,459 And of course, I could simply copy this once again 85 00:04:27,910 --> 00:04:30,829 and then I could paste, paste, paste, paste, 86 00:04:31,329 --> 00:04:32,589 run the command 87 00:04:32,959 --> 00:04:36,170 and take a look at that. All of a sudden 88 00:04:36,339 --> 00:04:38,989 we have an issue. Why? 89 00:04:39,339 --> 00:04:41,309 Well, that's because Python 90 00:04:41,779 --> 00:04:43,269 reads 91 00:04:43,859 --> 00:04:48,190 print text one and then again, immediately it sees another print text one, 92 00:04:48,200 --> 00:04:50,510 print text one, print text one 93 00:04:50,619 --> 00:04:52,619 that confuses Python. 94 00:04:52,630 --> 00:04:58,829 So what you want to do right now is we want to add these in separate lines. 95 00:04:58,839 --> 00:04:59,940 It's typically 96 00:05:00,160 --> 00:05:03,119 very good programming syntax, if we're going to run 97 00:05:03,239 --> 00:05:05,230 more than one function, 98 00:05:05,489 --> 00:05:08,339 you want to run them in separate lines, 99 00:05:08,429 --> 00:05:11,799 you should never run multiple functions within the same line. 100 00:05:11,809 --> 00:05:12,230 So 101 00:05:12,769 --> 00:05:13,929 I'm gonna go back in here, 102 00:05:14,070 --> 00:05:15,140 click on run 103 00:05:15,540 --> 00:05:19,470 and there it is, everything is back to normal. 104 00:05:19,690 --> 00:05:20,230 So 105 00:05:20,540 --> 00:05:24,950 that's just a very small snippet of what we're going to be dealing with. 106 00:05:24,959 --> 00:05:26,829 Obviously, we're going to be dealing with far more 107 00:05:27,200 --> 00:05:30,880 advanced functions and programs, but you know, 108 00:05:30,890 --> 00:05:33,799 step by step we're going to get there. 109 00:05:33,809 --> 00:05:34,989 So hopefully 110 00:05:35,299 --> 00:05:39,850 you now understand a bit better what variables are functions 111 00:05:40,299 --> 00:05:45,160 and how the syntax for Python works. Thank you for watching. 112 00:05:45,170 --> 00:05:46,959 I will see you in the next class.