WEBVTT 0 00:00.030 --> 00:01.800 Now that we've got our app working, 1 00:02.040 --> 00:04.770 you might think we've reached the end of today's lessons, 2 00:05.070 --> 00:08.010 but there's just one final thing I want to talk to you about. 3 00:08.550 --> 00:12.210 And that is the environment. Not the environment as a whole, 4 00:12.330 --> 00:15.510 but more precisely environment variables. 5 00:16.260 --> 00:18.510 Now what our environment variables anyways? 6 00:18.870 --> 00:20.760 If you go into your PyCharm project 7 00:20.880 --> 00:24.780 and you go into this tab where it says "Terminal", here 8 00:24.810 --> 00:27.840 if you type in env (set on Windows) and hit "Enter", 9 00:28.170 --> 00:31.020 you can see a whole bunch of variables. 10 00:31.050 --> 00:35.250 So you've got a key and a value 11 00:35.760 --> 00:39.270 and in between there is just a single equal (=) sign. 12 00:39.960 --> 00:44.790 So these are the different variables that are set in the environment in which 13 00:44.820 --> 00:45.720 your code is run. 14 00:46.350 --> 00:49.980 These variables have values which are strings 15 00:50.400 --> 00:54.300 which can be used in our applications or our code. 16 00:55.230 --> 00:56.490 Now inside Python 17 00:56.490 --> 01:00.750 anywhere you can also type env and you can see some slightly different 18 01:00.750 --> 01:05.100 environment variables which are relative to the Python anywhere environment. 19 01:05.580 --> 01:09.660 What exactly all these environment variables used for? Well, 20 01:09.840 --> 01:14.370 there's two major use cases. One is for convenience. 21 01:14.970 --> 01:18.690 Normally when you deploy a large application, 22 01:19.140 --> 01:23.340 the process is quite complicated. And once you've done it, 23 01:23.670 --> 01:28.230 you kind of don't want to mess around with the code base and update the code 24 01:28.230 --> 01:31.890 files like your main.py for example. Instead, 25 01:31.920 --> 01:36.450 you could have these environment variables, which you can change. For example, 26 01:36.510 --> 01:40.260 if you had an application that was sending you emails out to your clients, 27 01:40.500 --> 01:43.500 then your client base emails might change day to day. 28 01:44.070 --> 01:48.840 So certain variables that are being used in your code base could be set as 29 01:48.840 --> 01:49.980 environment variables 30 01:50.220 --> 01:53.640 and you can modify those variables without having to touch the code. 31 01:54.510 --> 01:57.480 A second reason might be for security. 32 01:58.140 --> 01:59.700 So when you're developing software, 33 01:59.730 --> 02:04.110 you might be uploading your code based somewhere, for example 34 02:04.110 --> 02:07.590 to store it online or to a service like PythonAnywhere. 35 02:08.520 --> 02:13.440 And it's usually not a good idea to have things like your authentication keys or 36 02:13.440 --> 02:18.440 your API keys to be stored in the same place as the rest of your code. 37 02:19.140 --> 02:21.180 That's where environment variables come in. 38 02:21.420 --> 02:26.420 So environment variables essentially allow us to separate out where we store 39 02:26.490 --> 02:28.590 our keys, our secret stuff, 40 02:28.800 --> 02:33.480 and various other variables away from where our code base is located. 41 02:34.140 --> 02:34.973 In our case, 42 02:35.010 --> 02:39.270 it doesn't really matter because we haven't got a paid account anywhere in here. 43 02:39.750 --> 02:44.370 It doesn't really matter if somebody steals our auth token or our API key, 44 02:44.490 --> 02:49.170 because none of those are linked to our payment details. Now, however, 45 02:49.170 --> 02:53.130 if we were to upgrade our accounts on open weather map's API 46 02:53.400 --> 02:54.900 or on Twilio's API, 47 02:55.200 --> 03:00.200 then we definitely want to keep these two things secret; auth token and the API 48 03:00.790 --> 03:01.623 key. 49 03:01.810 --> 03:05.860 Instead of having it located in the same place where we've got our code base 50 03:06.310 --> 03:10.210 which means you might accidentally upload it somewhere on the internet where 51 03:10.210 --> 03:12.610 other people can see it, instead, 52 03:12.640 --> 03:15.910 we can store these two things as environment variables. 53 03:16.600 --> 03:21.340 We can create an environment variable by simply typing export 54 03:21.760 --> 03:26.050 and then the name of the variable which I'll call OWM 55 03:26.410 --> 03:31.270 _API_KEY. And then it's really important that we have no spaces, 56 03:31.480 --> 03:33.640 but just a single equal sign. 57 03:34.360 --> 03:37.720 And then we're going to store everything that's in between the quotation marks. 58 03:38.020 --> 03:39.880 So I'm going to copy that from over here, 59 03:40.900 --> 03:45.430 and I'm going to paste that in here. Once I've exported that 60 03:46.180 --> 03:49.330 and then if I hit "env" again, you'll see 61 03:49.330 --> 03:51.370 now in this updated environment 62 03:51.430 --> 03:55.090 you can see that environment variable go in right there. 63 03:55.510 --> 04:00.100 And now we can tap into that environment variable in any of the code that we run 64 04:00.160 --> 04:05.160 from this particular environment. To do that we have to use this os module that 65 04:05.740 --> 04:06.573 we've already got. 66 04:06.940 --> 04:10.780 So I'm going to delete everything that's currently stored in the API key. 67 04:11.230 --> 04:15.250 And instead, I'm going to tap into os.environ, 68 04:16.030 --> 04:21.030 and then I'm going to use a method called get to get the value of a particular 69 04:21.070 --> 04:22.060 environment variable. 70 04:22.960 --> 04:26.500 The name is everything that's before the equal sign. 71 04:26.980 --> 04:31.960 So let's go ahead and paste it in here. And now when I run this code, 72 04:32.320 --> 04:36.010 so using python3 and then the name of the file, 73 04:36.760 --> 04:41.470 you can see that it successfully runs queuing our message into Twilio. 74 04:42.250 --> 04:45.730 Now go ahead and do the same thing with the auth token. 75 04:46.360 --> 04:48.520 You want to save this as an environment 76 04:48.520 --> 04:52.510 variable code auth_token in all caps, 77 04:52.900 --> 04:54.430 similar to what we've got here. 78 04:55.060 --> 04:58.390 And you want to store this value in the environment variable. 79 04:58.630 --> 05:02.850 Pause the video and give that a go. All right. 80 05:02.880 --> 05:06.090 So we're going to follow the exact same thing that we did before. We use the 81 05:06.090 --> 05:10.920 export keyword and then we type in the name of the environment variable 82 05:11.190 --> 05:15.420 which is going to be AUTH_TOKEN. And then really importantly, 83 05:15.450 --> 05:17.670 we just have an equal sign, no spaces, 84 05:18.090 --> 05:21.840 and we're going to store this value without the double-quotes 85 05:22.440 --> 05:26.970 and we're going to put it in here. Now in our environment variables, 86 05:27.000 --> 05:30.120 you can see we've got our open weather map API key. 87 05:30.540 --> 05:35.280 And if we scroll up a bit more, you can see our auth token as well. 88 05:36.750 --> 05:41.750 So now we can replace this string with our os.environ.get 89 05:43.560 --> 05:47.580 and then we pass in the name of the key which is AUTH_TOKEN. 90 05:48.630 --> 05:53.630 And now let's run our code again with python3 main.py. 91 05:54.090 --> 05:56.580 And you can see it's still works as before. 92 05:57.320 --> 06:01.730 But now if somebody comes across this particular code base on the internet, 93 06:02.030 --> 06:07.030 they won't be able to use our Twilio account or our open weather map account 94 06:07.460 --> 06:12.350 because both of these keys are now hidden. Let's go ahead and hit save. 95 06:13.760 --> 06:15.410 So now we're going to do the same thing, 96 06:15.680 --> 06:19.340 but at the point where we run our code from our task scheduler. 97 06:19.880 --> 06:24.590 So go ahead and right-click on this snake and then open the link in a new tab so 98 06:24.590 --> 06:27.470 that we can go to our tasks section. 99 06:27.920 --> 06:32.480 And here we're going to edit our command. Instead of just running Python main 100 06:32.480 --> 06:36.740 .py, we're going to export those two environment variables. 101 06:37.280 --> 06:41.810 This is why we've got two screens open up so we can actually copy the actual 102 06:41.900 --> 06:46.430 values. The first value is going to be our open weather map 103 06:46.460 --> 06:49.790 API key. So I'm going to copy that. And then here, 104 06:49.820 --> 06:54.470 I'm going to write export and then paste in that first key. Now, 105 06:54.500 --> 06:58.790 afterward, I'm going to use a semi-colon to denote a new line 106 06:59.210 --> 07:03.140 and then I'm going to export the next key. Scrolling up, 107 07:03.170 --> 07:07.220 we can see our auth token right here so we're going to copy that as well 108 07:07.550 --> 07:11.330 and we're going to export that as the other environment variable. 109 07:11.780 --> 07:14.480 And then finally, we're going to cap it off with a semicolon. 110 07:14.930 --> 07:18.860 So now you should have your export OWM_API_KEY 111 07:19.430 --> 07:23.750 and then your exporting your auth token as well. And then finally, 112 07:23.750 --> 07:26.960 on the last line, we're running our python3 main.py. 113 07:27.770 --> 07:31.550 Now let's change this to run at the current time. 114 07:31.550 --> 07:35.690 So it's going to be UTC time which happens to be 10 o'clock 115 07:35.720 --> 07:38.600 and then instead of 46, it's now 48 116 07:38.600 --> 07:43.340 so I'm going to change that to 49. And then I'm gonna hit the tick. 117 07:44.060 --> 07:47.120 And now we're going to wait to see if it actually works 118 07:47.330 --> 07:51.410 even though we've taken out the API keys from our main.py 119 07:51.650 --> 07:53.960 because we're exporting it in our command. 120 07:54.200 --> 07:56.870 Let's see if we still get the notification message. 121 07:58.490 --> 08:01.310 There you have it. It's still working as before. 122 08:02.180 --> 08:04.760 But now this is invisible to people 123 08:05.180 --> 08:07.910 if they happen to access our main.py. 124 08:08.510 --> 08:12.020 Now don't worry. The service of Python anywhere are pretty secure. 125 08:12.050 --> 08:14.000 Nobody's really going to hack into your account 126 08:14.300 --> 08:16.130 just to look into your main.py. 127 08:16.760 --> 08:20.390 The bigger problem is when you upload your own code to places like Git 128 08:20.390 --> 08:21.890 Hub or a BitBucket, 129 08:22.160 --> 08:25.580 basically places that are essentially a Dropbox for code. 130 08:26.150 --> 08:29.120 And when you have it on there, because your code could be public, 131 08:29.420 --> 08:31.280 that's where the problem happens. 132 08:31.580 --> 08:35.660 If people look at your code file and they see that you've got API keys in there, 133 08:35.660 --> 08:40.130 then they might steal them. So whenever you're uploading your code publicly, 134 08:40.310 --> 08:45.310 always be careful that you strip it of all of the API keys and instead use 135 08:45.560 --> 08:50.450 environment variables like we have here to pull it from the environment. 136 08:51.440 --> 08:56.070 All that's left to do for you is to update your latitude and longitude to your 137 08:56.070 --> 09:00.810 actual local latitude and longitude instead of the rainy place that we're 138 09:00.810 --> 09:05.550 testing. And you've now completed the rain alert application. 139 09:06.210 --> 09:08.970 Now I've showed you quite a few different APIs, 140 09:09.000 --> 09:12.300 but there's a whole world of APIs for you to explore. 141 09:12.810 --> 09:16.680 And if you have the patience to read their documentation and understand how to 142 09:16.680 --> 09:20.700 work with their APIs, then you now know how to work with their endpoints, 143 09:20.940 --> 09:25.560 how to pass parameters and also how to authenticate yourself with their servers. 144 09:26.100 --> 09:31.100 So here's a list of fun APIs that you can use to build applications with. 145 09:32.700 --> 09:37.700 I've shown you how you can make a rain alert and send yourself SMS messages, 146 09:38.520 --> 09:43.110 or how to get the location of the ISS or the sunrise and sunset times, 147 09:43.410 --> 09:48.090 but there's a whole bunch of other APIs for you to explore. For example, 148 09:48.090 --> 09:50.460 things like the open movie database API, 149 09:50.910 --> 09:53.970 which contains a whole bunch of movie related data, 150 09:54.390 --> 09:59.390 or looking up songs and artists using the Spotify API and a whole lot more. 151 10:00.840 --> 10:02.760 So I'll leave you to explore that. 152 10:03.090 --> 10:06.000 And if you come up with something innovative and interesting, 153 10:06.240 --> 10:10.380 be sure to share it with the rest of us in the Q&A below this lesson so that 154 10:10.380 --> 10:12.810 we can all check it out and admire your hard work.