WEBVTT 00:00.380 --> 00:07.640 When you're writing long numbers, you can group digits using underscores to make large numbers more 00:07.640 --> 00:08.420 readable. 00:08.570 --> 00:18.110 So for example, this let's make my value 14 000000000. 00:18.830 --> 00:19.390 That's it. 00:19.400 --> 00:23.540 So when you print a number that was defined using underscores. 00:23.750 --> 00:26.630 Python prints only the digits. 00:26.630 --> 00:30.500 So Python ignores the underscores when storing these kinds of values. 00:30.620 --> 00:33.080 Even if you don't group them. 00:33.200 --> 00:38.630 Digits in threes so the value will still be unaffected. 00:38.630 --> 00:42.200 So the two python 1000. 00:43.100 --> 00:45.240 1000 year. 00:47.710 --> 00:52.150 Is the same as one underscore three zeros. 00:53.760 --> 00:59.250 Which is the same as one zero underscore two zeros. 00:59.910 --> 01:04.710 This feature works for both integer and floats. 01:04.830 --> 01:11.970 We can also multiple assignment here so you can assign values to more than one variable using just a 01:11.970 --> 01:13.380 single line of code. 01:13.410 --> 01:19.830 So this can help shorten your programs and make the make them easier to read. 01:19.860 --> 01:23.400 So you will use this technique most often when initializing. 01:24.740 --> 01:26.330 Numbers, For example. 01:26.330 --> 01:27.530 Here. 01:28.220 --> 01:29.030 Here. 01:30.570 --> 01:35.970 You can initialize the variables X or a B. 01:36.870 --> 01:40.800 T2000. 01:41.810 --> 01:46.610 So we need to separate the variable names with commas. 01:47.380 --> 01:48.520 Here like this. 01:51.120 --> 01:59.530 It's a separate variable names with commas here and do the same with the values here. 01:59.660 --> 02:00.890 These are the variables. 02:00.890 --> 02:03.680 Remember every time variables. 02:04.450 --> 02:08.470 And these are the values. 02:12.000 --> 02:15.200 So this is my value is variables. 02:16.420 --> 02:16.690 Um. 02:17.320 --> 02:17.970 Yes. 02:17.980 --> 02:18.340 Variable. 02:18.340 --> 02:18.900 So we will. 02:22.140 --> 02:22.890 So. 02:24.390 --> 02:30.540 As long as the number of values matches the number of variables, Python will match them correctly. 02:30.540 --> 02:33.780 Here we have three numbers and three variables. 02:34.830 --> 02:36.240 One, two, three. 02:36.450 --> 02:38.210 One, two, three. 02:38.220 --> 02:38.910 Variable. 02:39.610 --> 02:41.500 And that's it. 02:42.410 --> 02:43.280 They are this out. 02:46.280 --> 02:47.030 So. 02:50.220 --> 02:50.640 We have. 02:50.730 --> 02:52.500 We also have constants in. 02:53.770 --> 02:54.240 Python. 02:54.250 --> 03:02.740 So a constant is a variable whose value stays the same throughout life of a program. 03:02.740 --> 03:05.140 So actually, let me write that constants here. 03:05.140 --> 03:07.330 So let's define that. 03:07.600 --> 03:08.440 So. 03:11.980 --> 03:12.510 Owens. 03:15.590 --> 03:21.770 So constant is basically like you are locking the your variable name. 03:22.010 --> 03:24.650 Let's throw a log log here. 03:38.010 --> 03:41.730 With constant you are locking your. 03:43.460 --> 03:45.140 Variable value. 03:45.170 --> 03:46.550 So here. 03:48.990 --> 03:57.090 A python doesn't have built in constant types, but Python programs use all capital letters to indicate 03:57.090 --> 04:02.160 a variable will be treated as constant and never be changed. 04:02.190 --> 04:09.990 Here we can do, for example, max connections and 5000 here. 04:10.020 --> 04:15.600 So when you want to treat a variable as a constant in your code, write the name of the variable in 04:15.600 --> 04:17.670 all capital letters. 04:19.270 --> 04:22.990 We also have a comment in Python. 04:24.240 --> 04:26.460 Which you will learn in next lecture.