Would you like to inspect the original subtitles? These are the user uploaded subtitles that are being translated:
1
00:00:00,350 --> 00:00:04,530
If you're not sure what type a given value has,
2
00:00:04,530 --> 00:00:07,620
then Python has a nice function called type,
3
00:00:07,620 --> 00:00:11,955
and what type does is it tells us what the type of a given value is.
4
00:00:11,955 --> 00:00:17,560
So, for example if we print out the value of type when called with the string "Hello,
5
00:00:17,560 --> 00:00:22,035
world" as an argument then Python is going to tell us that this is a string.
6
00:00:22,035 --> 00:00:25,290
It'll tell us that this isn't int,
7
00:00:25,290 --> 00:00:30,210
and then here if we don't call the type function we get the value itself,
8
00:00:30,210 --> 00:00:36,330
but if we print out the type of 3.2 then we get that this is a float.
9
00:00:36,330 --> 00:00:38,960
So let's run our code and what you'll
10
00:00:38,960 --> 00:00:42,845
see is that when we print out the type of Hello world.
11
00:00:42,845 --> 00:00:47,870
Then Python has a way of telling us that this is a string.
12
00:00:47,870 --> 00:00:53,465
Print out the type of 17 Python is telling us this is an integer.
13
00:00:53,465 --> 00:00:56,990
This is just us printing out the string hello world itself,
14
00:00:56,990 --> 00:01:02,840
but if we print out the type of 3.2 then Python tells us that this is a float,
15
00:01:02,840 --> 00:01:06,170
and this can be especially helpful in situations where
16
00:01:06,170 --> 00:01:09,145
you're not necessarily sure what type something has.
17
00:01:09,145 --> 00:01:13,085
So for example here we have a value 17,
18
00:01:13,085 --> 00:01:16,550
and even though this is a number because it's in quotation
19
00:01:16,550 --> 00:01:20,600
marks the value of this expression is going to be a string.
20
00:01:20,600 --> 00:01:24,560
So the type of this expression is going to print out class str.
21
00:01:24,560 --> 00:01:25,835
Same thing with this.
22
00:01:25,835 --> 00:01:29,330
So even though 3.2 is a float because these are in quotation
23
00:01:29,330 --> 00:01:33,015
marks this overall expression is a string.
24
00:01:33,015 --> 00:01:36,875
So if I run my code then I'll see that both of these are strings.
25
00:01:36,875 --> 00:01:41,260
Now there are few other things to note when working with Python expressions.
26
00:01:41,260 --> 00:01:43,440
First, when creating a string,
27
00:01:43,440 --> 00:01:47,075
as we mentioned, there are multiple ways of creating a string literal.
28
00:01:47,075 --> 00:01:49,445
One is using a single quotes mark.
29
00:01:49,445 --> 00:01:52,040
Another is using double quotation marks.
30
00:01:52,040 --> 00:01:58,430
Another is using three double quotation marks or three single quotation marks.
31
00:01:58,430 --> 00:02:01,175
Now, the important thing to note is that
32
00:02:01,175 --> 00:02:04,440
even though all of these expressions create a string in
33
00:02:04,440 --> 00:02:08,120
a different way if we ask what's the type of each of
34
00:02:08,120 --> 00:02:12,160
these then Python is going to tell us that these are all strings.
35
00:02:12,160 --> 00:02:16,010
So even though we create strings in four different ways
36
00:02:16,010 --> 00:02:20,765
here all of these boil down to the same type in Python,
37
00:02:20,765 --> 00:02:23,310
which is a string.
38
00:02:23,310 --> 00:02:26,750
So another thing to note when creating strings is that sometimes you
39
00:02:26,750 --> 00:02:30,390
want to include single or double quotation marks inside of a string.
40
00:02:30,390 --> 00:02:33,275
So for example I might want to print out
41
00:02:33,275 --> 00:02:40,450
the string 'Bruce's beard'.
42
00:02:40,450 --> 00:02:43,930
Now here you'll note that I have an apostrophe in
43
00:02:43,930 --> 00:02:49,210
Bruce's and when I try to run my code then Python gives me
44
00:02:49,210 --> 00:02:54,070
a syntax error and that's because to Python it thinks that this is the string
45
00:02:54,070 --> 00:02:56,800
because it thinks that this quotation mark starts
46
00:02:56,800 --> 00:03:00,410
the string in that the apostrophe is supposed to end it.
47
00:03:00,410 --> 00:03:03,340
One way to get around this is by using
48
00:03:03,340 --> 00:03:05,500
double quotation marks if we know that we're
49
00:03:05,500 --> 00:03:08,690
going to have an apostrophe inside of our string.
50
00:03:09,870 --> 00:03:13,130
So here this works.
51
00:03:13,130 --> 00:03:19,730
Conversely, if we had a string that we knew would contain double quotation marks,
52
00:03:21,360 --> 00:03:25,190
again if I run this code then I get a syntax error because
53
00:03:25,190 --> 00:03:29,209
Python thinks the string starts here and ends here,
54
00:03:29,209 --> 00:03:35,520
but one way around it is by using single quotation marks to create the string.
55
00:03:36,610 --> 00:03:41,060
If I have a string that might contain single and double quotation marks,
56
00:03:41,060 --> 00:03:44,310
then one way around that is by using triple quotation marks.
57
00:03:44,310 --> 00:03:48,030
So I might say something like," Oh no",
58
00:03:48,030 --> 00:03:53,890
she exclaimed, "Ben's bike is broken!"
59
00:03:56,920 --> 00:04:04,235
So now I can use both double and single quotation marks inside of the string,
60
00:04:04,235 --> 00:04:09,680
and again triple quotation marks allow us to create strings that span several lines.
61
00:04:09,680 --> 00:04:13,940
Another thing to note when creating an integer is that in the US we
62
00:04:13,940 --> 00:04:18,170
often use commas every third digit in larger numbers.
63
00:04:18,170 --> 00:04:23,720
So for example we might indicate 42,500 using a comma like this,
64
00:04:23,720 --> 00:04:27,030
but here if Python sees a comma inside of
65
00:04:27,030 --> 00:04:30,620
the integer it thinks that these are two separate values.
66
00:04:30,620 --> 00:04:36,035
So it thinks that we're printing out 42 and then 500 as separate values.
67
00:04:36,035 --> 00:04:39,140
So when we're creating large numbers in Python we
68
00:04:39,140 --> 00:04:42,810
shouldn't ever use commas to separate out every three digits.
69
00:04:42,810 --> 00:04:50,530
We need to write the integer like this and now we have the number 42500 in one value.
70
00:04:50,530 --> 00:04:53,870
One more thing to note along those lines is that we can call
71
00:04:53,870 --> 00:04:57,215
print with any number of arguments and when we do,
72
00:04:57,215 --> 00:05:00,405
print decides to take every argument and printout
73
00:05:00,405 --> 00:05:03,860
it's value separated by spaces instead of commas.
74
00:05:03,860 --> 00:05:06,830
So here we're printing out all of these values on
75
00:05:06,830 --> 00:05:11,970
one line and then all of these values on the next line.
76
00:05:12,640 --> 00:05:15,425
So let's do a few multiple choice.
77
00:05:15,425 --> 00:05:18,095
How can you determine the type of the variable?
78
00:05:18,095 --> 00:05:24,090
Well, one way to determine the type of the variable is by using the type function.
79
00:05:24,680 --> 00:05:30,285
Next question is what is the data type of: This is what kind of data?
80
00:05:30,285 --> 00:05:35,830
So in other words if we called type on this expression then what would we get?
81
00:05:35,830 --> 00:05:38,585
Well, Python would tell us that this is a string
82
00:05:38,585 --> 00:05:41,645
because it starts and ends with a single quotation mark.
83
00:05:41,645 --> 00:05:44,790
That's all for now. Until next time.7513
Can't find what you're looking for?
Get subtitles in any language from opensubtitles.com, and translate them here.