Random Numbers

Quick reference

• 00:04 Okay, in this video I want to show you how to work with random numbers with Python.
• 00:07 And we're going to use this later on to generate dummy data,
• 00:11 fake numbers to populate our Excel spreadsheets.
• 00:15 when working on some projects.
• 00:16 So random numbers with Python are actually very, very easy.
• 00:20 We just have to import the random library from Python.
• 00:24 So we can do that up here, we can go from random, import random.
• 00:30 Now this will import the random library, which will generate random numbers, but
• 00:34 they're not really the kind of random numbers we want.
• 00:36 And you'll see what I mean right now.
• 00:38 So let's just create one and we do that by just calling the random function.
• 00:41 Right. So, if we wanted to print this
• 00:43 to the screen, we could wrap this whole thing in our print function like we've
• 00:46 done before, and I've saved this file as rand.pi.
• 00:49 So, go ahead and save this, head over to our terminal and let's run this file.
• 00:54 And when we do you see we get this random number.
• 00:56 Now this is a decimal number.
• 00:58 What we call a float 0.67, whatever.
• 01:02 If we we run this again, we get another random number.
• 01:05 But again, this is not a particularly useful number usually.
• 01:08 We usually want integers, whole numbers, right?
• 01:11 And, in order to use whole numbers, we need something else.
• 01:14 So we can go from random import randint.
• 01:20 And this will allow us to create random integers.
• 01:23 And like I said integers are just whole numbers like four, 27, 18, right?
• 01:29 So, to use this It's a little bit different.
• 01:32 Let's create a variable for this.
• 01:33 Let's call this my_rand.
• 01:36 And we can call randint.
• 01:38 And this is a function and now we need to pass in a range.
• 01:42 So, we need to tell Python where we want to grab our number from.
• 01:46 So, let's say from 0 to 100 or even just from 0 to 10.
• 01:51 So now, we can print out my_rand and
• 01:55 this will print out a number between 0 and 10.
• 01:59 It can be 0, it can be 10, it can be any number in between.
• 02:03 So, it might be 0, and might be 4, it might be 8, and it might be 10.
• 02:08 Right? So, okay, let's go ahead and
• 02:09 save this and run it.
• 02:11 And see what we got, and we get 5.
• 02:14 We run this again.
• 02:16 We get 4, we run this again.
• 02:17 We get 10.
• 02:18 So, it's really just that easy to generate random numbers with Python.
• 02:23 And this is a really useful sort of thing to know, not just for this Excel course,
• 02:27 but for any sort of Python programming.
• 02:29 So, now let's put this together with our for
• 02:31 loop that we learned in the last video.
• 02:33 And let's put a little spin on it, so let's create a for loop.
• 02:36 And I'm going to call for number in.
• 02:40 Now instead of looping through a list or
• 02:42 something we can look we can loop through just a number of times, a range of times,
• 02:46 and we can do that by calling the range function.
• 02:49 And then we can say, how many times do we want to loop through this, so
• 02:52 let's loop through this 10 times.
• 02:55 What do we want to do each time?
• 02:56 Well, let's just create another random number and let's comment this one out.
• 03:00 And then let's just print out that.
• 03:06 That random number.
• 03:07 So, every time we loop through here, and we're going to loop through here 10 times,
• 03:10 we're going to generate a random integer and then just print it out.
• 03:13 Let's go ahead and save this and run it.
• 03:15 And see what we got.
• 03:17 And we see 1, 6, 10, 8, 1, 1,
• 03:20 1 since it's random it could be a bunch of ones in a row, you never know.
• 03:26 So, let's run this again and we get a whole other list of random numbers.
• 03:31 Clear the screen and run it again.
• 03:34 Again, here's 0 because it can be 0, it can be 10.
• 03:36 It could be any number in between.
• 03:37 And it's very cool.
• 03:38 So, quick and easy way to generate as many random numbers as you want,
• 03:42 we could generate 1,000 of them, right?
• 03:45 So we could save this.
• 03:47 And if we run this, if we scroll up here we'll know,
• 03:51 we'll see, we've got so many random numbers.
• 03:56 And if you counted them all there would be 1,000.
• 03:58 We could change this to 10.
• 04:00 And we could say from 0 to 1,000 but our range of random numbers.
• 04:08 If we save this and run it.
• 04:13 We see we get bigger numbers.
• 04:15 So very, very cool.
• 04:16 We don't have to start at zero.
• 04:18 We could start at between100 and say 150.
• 04:25 We save this and run it.
• 04:28 You'll notice that all these numbers are between 100 and 150.
• 04:31 So, any kind of random numbers you want to generate in any sort of range,
• 04:34 you have complete control over this.
• 04:36 If you want something besides just integers and you just want decimals,
• 04:41 you can use the random that we used at the beginning of this video.
• 04:46 And, very cool.
• 04:47 So, that's how to create random numbers.
• 04:48 That's how to create range in our for loop.
• 04:51 That's going to be useful to us later on.
• 04:53 And that's all there is to it.
• 04:54 So I think that's all for the Python programming of this course.
• 04:57 In the next video, we're going to jump right into open PI Excel.

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