1
00:00:00,120 --> 00:00:01,380
All right. So again,

2
00:00:01,380 --> 00:00:05,400
it's time to put theory into practice and get some hands-on action.

3
00:00:05,760 --> 00:00:10,560
You should be able to find the day 1.3 assignment which is inputs.

4
00:00:11,070 --> 00:00:15,300
Click on it and you will see the instructions for this particular challenge.

5
00:00:15,720 --> 00:00:18,420
And the idea is that you're going to write a program

6
00:00:18,450 --> 00:00:22,950
that's going to print the number of characters in a user's name. For example,

7
00:00:22,950 --> 00:00:25,980
if I input my name, which is Angela,

8
00:00:26,370 --> 00:00:31,370
it should output the number six because there are six characters in the word,

9
00:00:32,190 --> 00:00:36,390
Angela. But remember you can't just print out the number six,

10
00:00:36,450 --> 00:00:38,430
because when I'm checking for this code,

11
00:00:38,700 --> 00:00:42,720
I'm going to try a whole bunch of different names as the input.

12
00:00:43,170 --> 00:00:46,650
And you're going to have to use a little bit of thinking,

13
00:00:47,010 --> 00:00:51,810
a little bit of Googling and also a little bit of messing around with the code

14
00:00:51,840 --> 00:00:54,570
in order to get it to work. If you need any help,

15
00:00:54,600 --> 00:00:58,140
there's a few hints down here for you. And if you really get stuck,

16
00:00:58,350 --> 00:01:00,390
then you can take a look at the solution,

17
00:01:00,450 --> 00:01:03,510
but not until you've really given it a go. And I really,

18
00:01:03,510 --> 00:01:05,400
really want to know that you've tried hard.

19
00:01:06,330 --> 00:01:09,720
And the whole point of these exercises is you sit there and scratch your head a

20
00:01:09,720 --> 00:01:12,420
little bit and actually give it a good go.

21
00:01:13,410 --> 00:01:17,940
So I'm going to stop talking now and I'm going to let you pause the video and

22
00:01:17,940 --> 00:01:20,160
try to complete this challenge. All right, good luck.

23
00:01:23,610 --> 00:01:27,720
Okay. So how did that go? If you get stuck, I want to tell you

24
00:01:27,990 --> 00:01:32,160
the programmers secret to getting unstuck

25
00:01:32,760 --> 00:01:37,170
which is go and grab yourself a cup of tea, have a quick break,

26
00:01:37,410 --> 00:01:39,240
look at something else for a little moment,

27
00:01:39,480 --> 00:01:42,990
think about something else and then come back to it. Well,

28
00:01:42,990 --> 00:01:46,140
the tea part is optional. Well, at least if you're outside of England,

29
00:01:46,170 --> 00:01:50,640
it's optional. So let's get started solving this challenge.

30
00:01:50,820 --> 00:01:54,810
So the idea is that we're going to create a program that counts the number of

31
00:01:54,810 --> 00:01:57,540
characters in any user's name.

32
00:01:58,050 --> 00:02:02,280
And that name is obviously going to come through an input function,

33
00:02:02,730 --> 00:02:07,350
and then we're going to use a function that calculates the length of a string

34
00:02:07,680 --> 00:02:10,770
and we're going to send that out as the output.

35
00:02:11,850 --> 00:02:15,600
The first thing we'll probably need is some form of input function right?

36
00:02:16,080 --> 00:02:20,460
And the prompt that we're going to give the user is what is your name or

37
00:02:20,490 --> 00:02:23,040
something similar that asks them for their name.

38
00:02:23,520 --> 00:02:28,050
And I like to add a space at the end of the prompt. This way, when you run it,

39
00:02:28,230 --> 00:02:33,180
you don't actually have that cursor straight next to the, um, the question mark

40
00:02:33,180 --> 00:02:37,980
which looks a bit weird. But either way, once we've entered an input,

41
00:02:38,340 --> 00:02:42,390
then this part gets replaced by that input

42
00:02:42,660 --> 00:02:43,950
and we're going to do something with it.

43
00:02:43,980 --> 00:02:47,220
We're going to calculate the length of that string.

44
00:02:47,700 --> 00:02:52,230
Now using our eyes, we can obviously see that it's six characters long.

45
00:02:52,560 --> 00:02:55,770
But what if you have a really a long name?

46
00:02:56,700 --> 00:03:00,940
So let's go ahead and take a look at how we might figure out,

47
00:03:01,300 --> 00:03:05,590
um, how to you get a function that calculates the length of a string.

48
00:03:06,100 --> 00:03:09,520
I've actually included the Google search that you might need to use.

49
00:03:10,300 --> 00:03:13,090
And so let's just paste that URL in here,

50
00:03:13,180 --> 00:03:17,740
and you can see that we're searching for how to get the length of the string in

51
00:03:17,800 --> 00:03:21,400
Python and we're trying to get results from Stack Overflow.

52
00:03:21,820 --> 00:03:26,820
The first result is a question that seems to pretty match match exactly what we

53
00:03:27,040 --> 00:03:31,810
want. And the answer from user 225312

54
00:03:31,810 --> 00:03:36,810
tells us that you need to use the Len function. And the way that you use it

55
00:03:37,630 --> 00:03:41,170
is by passing the string inside the parentheses.

56
00:03:41,740 --> 00:03:45,730
Now this part might look a little bit different from what you're used to with the

57
00:03:45,730 --> 00:03:46,930
equal sign and everything.

58
00:03:47,230 --> 00:03:50,140
But I have confidence that if you mess around with this code,

59
00:03:50,350 --> 00:03:51,790
you'll be able to figure it out.

60
00:03:52,840 --> 00:03:56,320
Just like what we did with print or input,

61
00:03:56,620 --> 00:04:01,620
the Len function also has a set of parentheses and it will work its magic on

62
00:04:03,010 --> 00:04:07,480
whatever it is that we put inside the parentheses. If I just put my name,

63
00:04:07,540 --> 00:04:08,373
Angela here,

64
00:04:08,440 --> 00:04:13,440
let's just comment out the previous line, and I go ahead and print the result of

65
00:04:14,260 --> 00:04:18,700
this and then I hit run, you can see that it prints 6. Now,

66
00:04:18,700 --> 00:04:22,330
if I change that to Jack, then you'll see it prints 4.

67
00:04:22,480 --> 00:04:24,970
So it will print whatever it is

68
00:04:25,000 --> 00:04:29,680
the length of the string that I've put inside the Len function.

69
00:04:30,220 --> 00:04:31,900
So we're getting close now, right?

70
00:04:32,110 --> 00:04:36,160
Because instead of printing out a string that I've hard coded here,

71
00:04:36,550 --> 00:04:40,540
what I want is to take the input that the user has given me.

72
00:04:40,960 --> 00:04:44,500
So something like this. Now, if you want to,

73
00:04:44,500 --> 00:04:49,390
you can actually add some spaces inside here just to make it a little bit

74
00:04:49,390 --> 00:04:54,390
clearer to yourself as to what's actually going on because there's three

75
00:04:54,610 --> 00:04:57,490
functions here. They are all nested inside each other.

76
00:04:57,910 --> 00:04:59,680
So this is the first one,

77
00:04:59,680 --> 00:05:03,430
this is the one that is going to get the input from the user and replace this

78
00:05:03,430 --> 00:05:06,250
part with whatever it is that they type down here.

79
00:05:06,910 --> 00:05:11,910
Then that string gets calculated using the Len function to get the length of

80
00:05:12,610 --> 00:05:16,990
that string. And then that number will get printed by the print function.

81
00:05:18,190 --> 00:05:21,640
Now let's go ahead and hit run and let's give it a go.

82
00:05:21,730 --> 00:05:24,550
So let's try Jack, hit enter.

83
00:05:24,790 --> 00:05:27,130
And it tells us that it's 4.

84
00:05:27,700 --> 00:05:29,830
But using the same line of code,

85
00:05:29,950 --> 00:05:34,180
if we try a different name Angela, then it prints out six.

86
00:05:34,930 --> 00:05:37,960
How did you get on with this? If you got stuck,

87
00:05:38,110 --> 00:05:42,160
then have a look at the solution Repl.it um,

88
00:05:42,190 --> 00:05:46,480
where you will be able to find the code that I've written here and a little bit

89
00:05:46,480 --> 00:05:47,890
of explanation as well.

90
00:05:48,730 --> 00:05:51,790
The important thing is that you really play around with this code.

91
00:05:52,150 --> 00:05:57,150
Try things and make it break and make it work and just get it to do what you

92
00:05:58,610 --> 00:05:59,443
want it to do.

93
00:06:00,020 --> 00:06:05,020
And remember that if you ever want to visualize these things and the order of

94
00:06:06,200 --> 00:06:10,700
execution, then you can always use Thonny to see that.

95
00:06:10,880 --> 00:06:12,620
So let's go ahead and step in.

96
00:06:13,010 --> 00:06:17,420
You'll see that it goes through Len, input, and then it's going to carry out this

97
00:06:17,450 --> 00:06:21,650
functionality input. I gave it my name, hit enter.

98
00:06:22,250 --> 00:06:25,580
Then it puts that inside the Len function like so,

99
00:06:25,880 --> 00:06:28,040
so now the next step is this part.

100
00:06:28,280 --> 00:06:30,590
We're going to calculate the length of this string.

101
00:06:31,100 --> 00:06:34,490
And as I continue stepping into it, you can see that become six.

102
00:06:34,820 --> 00:06:37,430
And finally we're gonna carry out the final instruction,

103
00:06:37,460 --> 00:06:41,870
which is just to print six down here. Again,

104
00:06:42,050 --> 00:06:45,890
this can be quite useful just to visualize all the steps that are happening

105
00:06:46,460 --> 00:06:47,293
if you want to.

106
00:06:48,260 --> 00:06:52,490
Once you're done, head over to the next lesson and I'm going to talk to you

107
00:06:52,730 --> 00:06:57,730
all about Python variables and how we'll be able to identify pieces of data in

108
00:06:58,070 --> 00:07:01,520
our code. So for all of that, and more, I'll see you there.