1 00:00:00,380 --> 00:00:07,640 When you're writing long numbers, you can group digits using underscores to make large numbers more 2 00:00:07,640 --> 00:00:08,420 readable. 3 00:00:08,570 --> 00:00:18,110 So for example, this let's make my value 14 000000000. 4 00:00:18,830 --> 00:00:19,390 That's it. 5 00:00:19,400 --> 00:00:23,540 So when you print a number that was defined using underscores. 6 00:00:23,750 --> 00:00:26,630 Python prints only the digits. 7 00:00:26,630 --> 00:00:30,500 So Python ignores the underscores when storing these kinds of values. 8 00:00:30,620 --> 00:00:33,080 Even if you don't group them. 9 00:00:33,200 --> 00:00:38,630 Digits in threes so the value will still be unaffected. 10 00:00:38,630 --> 00:00:42,200 So the two python 1000. 11 00:00:43,100 --> 00:00:45,240 1000 year. 12 00:00:47,710 --> 00:00:52,150 Is the same as one underscore three zeros. 13 00:00:53,760 --> 00:00:59,250 Which is the same as one zero underscore two zeros. 14 00:00:59,910 --> 00:01:04,710 This feature works for both integer and floats. 15 00:01:04,830 --> 00:01:11,970 We can also multiple assignment here so you can assign values to more than one variable using just a 16 00:01:11,970 --> 00:01:13,380 single line of code. 17 00:01:13,410 --> 00:01:19,830 So this can help shorten your programs and make the make them easier to read. 18 00:01:19,860 --> 00:01:23,400 So you will use this technique most often when initializing. 19 00:01:24,740 --> 00:01:26,330 Numbers, For example. 20 00:01:26,330 --> 00:01:27,530 Here. 21 00:01:28,220 --> 00:01:29,030 Here. 22 00:01:30,570 --> 00:01:35,970 You can initialize the variables X or a B. 23 00:01:36,870 --> 00:01:40,800 T2000. 24 00:01:41,810 --> 00:01:46,610 So we need to separate the variable names with commas. 25 00:01:47,380 --> 00:01:48,520 Here like this. 26 00:01:51,120 --> 00:01:59,530 It's a separate variable names with commas here and do the same with the values here. 27 00:01:59,660 --> 00:02:00,890 These are the variables. 28 00:02:00,890 --> 00:02:03,680 Remember every time variables. 29 00:02:04,450 --> 00:02:08,470 And these are the values. 30 00:02:12,000 --> 00:02:15,200 So this is my value is variables. 31 00:02:16,420 --> 00:02:16,690 Um. 32 00:02:17,320 --> 00:02:17,970 Yes. 33 00:02:17,980 --> 00:02:18,340 Variable. 34 00:02:18,340 --> 00:02:18,900 So we will. 35 00:02:22,140 --> 00:02:22,890 So. 36 00:02:24,390 --> 00:02:30,540 As long as the number of values matches the number of variables, Python will match them correctly. 37 00:02:30,540 --> 00:02:33,780 Here we have three numbers and three variables. 38 00:02:34,830 --> 00:02:36,240 One, two, three. 39 00:02:36,450 --> 00:02:38,210 One, two, three. 40 00:02:38,220 --> 00:02:38,910 Variable. 41 00:02:39,610 --> 00:02:41,500 And that's it. 42 00:02:42,410 --> 00:02:43,280 They are this out. 43 00:02:46,280 --> 00:02:47,030 So. 44 00:02:50,220 --> 00:02:50,640 We have. 45 00:02:50,730 --> 00:02:52,500 We also have constants in. 46 00:02:53,770 --> 00:02:54,240 Python. 47 00:02:54,250 --> 00:03:02,740 So a constant is a variable whose value stays the same throughout life of a program. 48 00:03:02,740 --> 00:03:05,140 So actually, let me write that constants here. 49 00:03:05,140 --> 00:03:07,330 So let's define that. 50 00:03:07,600 --> 00:03:08,440 So. 51 00:03:11,980 --> 00:03:12,510 Owens. 52 00:03:15,590 --> 00:03:21,770 So constant is basically like you are locking the your variable name. 53 00:03:22,010 --> 00:03:24,650 Let's throw a log log here. 54 00:03:38,010 --> 00:03:41,730 With constant you are locking your. 55 00:03:43,460 --> 00:03:45,140 Variable value. 56 00:03:45,170 --> 00:03:46,550 So here. 57 00:03:48,990 --> 00:03:57,090 A python doesn't have built in constant types, but Python programs use all capital letters to indicate 58 00:03:57,090 --> 00:04:02,160 a variable will be treated as constant and never be changed. 59 00:04:02,190 --> 00:04:09,990 Here we can do, for example, max connections and 5000 here. 60 00:04:10,020 --> 00:04:15,600 So when you want to treat a variable as a constant in your code, write the name of the variable in 61 00:04:15,600 --> 00:04:17,670 all capital letters. 62 00:04:19,270 --> 00:04:22,990 We also have a comment in Python. 63 00:04:24,240 --> 00:04:26,460 Which you will learn in next lecture.