WEBVTT 1 00:00:00.380 --> 00:00:01.800 Hi guys, and welcome back, 2 00:00:01.800 --> 00:00:03.290 in this video we're going to be adding 3 00:00:03.290 --> 00:00:06.860 the vote date to our votes in the polling app. 4 00:00:06.860 --> 00:00:07.963 So let's get started. 5 00:00:09.260 --> 00:00:11.880 We're gonna start off by opening database.py 6 00:00:11.880 --> 00:00:16.870 and we want to add a new column into the votes table. 7 00:00:16.870 --> 00:00:19.280 So, oh by the way, I've got an old import there, 8 00:00:19.280 --> 00:00:21.300 so we're gonna do that, in create votes, 9 00:00:21.300 --> 00:00:23.830 we have the username, the option ID, 10 00:00:23.830 --> 00:00:27.580 an now we're also gonna add the vote timestamp, 11 00:00:27.580 --> 00:00:31.010 which is going to be a integer. 12 00:00:31.010 --> 00:00:33.490 Make sure that because we're changing the table, 13 00:00:33.490 --> 00:00:35.530 we have to go into ElephantSQL, 14 00:00:35.530 --> 00:00:37.150 or your server of choice, 15 00:00:37.150 --> 00:00:40.210 and delete the votes table from there. 16 00:00:40.210 --> 00:00:43.285 Otherwise, whenever you try to insert a new vote, 17 00:00:43.285 --> 00:00:47.180 into this table, your gonna find that the existing table 18 00:00:47.180 --> 00:00:49.320 doesn't have enough columns. 19 00:00:49.320 --> 00:00:51.110 So something else that we have to do here of course, 20 00:00:51.110 --> 00:00:54.020 is go ahead and change the insert vote here 21 00:00:54.020 --> 00:00:56.410 as well as the username and option ID, 22 00:00:56.410 --> 00:00:59.076 we have to enter the vote timestamp 23 00:00:59.076 --> 00:01:04.076 and the values do require the third parameter there. 24 00:01:04.490 --> 00:01:07.681 Now let's go over to add poll vote down here. 25 00:01:07.681 --> 00:01:09.360 And we're just gonna make sure that, 26 00:01:09.360 --> 00:01:11.750 as well as the username and the option ID, 27 00:01:11.750 --> 00:01:14.760 we get the timestamp, I'm gonna put it down here 28 00:01:14.760 --> 00:01:17.240 in the middle, so I'm gonna do vote timestamp, 29 00:01:17.240 --> 00:01:20.080 it's gonna be a float, and we're gonna pass it in there. 30 00:01:20.080 --> 00:01:23.080 Notice that we're putting an integer into the database 31 00:01:23.080 --> 00:01:25.520 as opposed to a float, that's just gonna lose everything 32 00:01:25.520 --> 00:01:27.530 after the decimal place and that's okay, 33 00:01:27.530 --> 00:01:29.610 we don't really care about which microsecond 34 00:01:29.610 --> 00:01:31.680 somebody voted in, maybe we would, 35 00:01:31.680 --> 00:01:34.050 if we were doing something a bit more like politics, 36 00:01:34.050 --> 00:01:36.060 voting, or something like that. 37 00:01:36.060 --> 00:01:38.796 But for here, we can covert from floats to integers 38 00:01:38.796 --> 00:01:41.070 and lose everything after the decimal point 39 00:01:41.070 --> 00:01:44.420 and that's okay and then we're going to add this in, 40 00:01:44.420 --> 00:01:46.630 but I do realise that 41 00:01:47.810 --> 00:01:49.350 we need to put that in there 42 00:01:49.350 --> 00:01:50.970 and just because the username, option ID, 43 00:01:50.970 --> 00:01:52.570 and vote timestamp have to match 44 00:01:52.570 --> 00:01:55.440 the order of the columns that we're putting in here. 45 00:01:55.440 --> 00:01:58.820 All right so this is how we insert a vote. 46 00:01:58.820 --> 00:02:02.330 Now, whenever we're selecting a vote, from here, 47 00:02:02.330 --> 00:02:05.100 get votes for option, this is gonna return everything, 48 00:02:05.100 --> 00:02:07.790 so that means we're gonna get the timestamp in here as well. 49 00:02:07.790 --> 00:02:10.100 We're gonna deal with that in a moment. 50 00:02:10.100 --> 00:02:13.560 The first thing though is gonna go to option.py 51 00:02:13.560 --> 00:02:16.920 and here, when we're voting, we need to change this slightly 52 00:02:16.920 --> 00:02:19.745 because now we have to pass in the timestamp. 53 00:02:19.745 --> 00:02:24.000 And we know that we have to pass in the UTC timestamp, 54 00:02:24.000 --> 00:02:25.570 not the local time. 55 00:02:25.570 --> 00:02:28.880 So let's do it, using what we learned in the last lecture. 56 00:02:28.880 --> 00:02:33.070 We can do current datetime as UTC and in the last video, 57 00:02:33.070 --> 00:02:36.310 we learned a way to get the current datetime as a UTC, 58 00:02:36.310 --> 00:02:39.470 which was getting the UTC timezone from pytz 59 00:02:39.470 --> 00:02:42.910 and then using that to localise the naive datetime, 60 00:02:42.910 --> 00:02:45.860 but we can do it with datetime.datetime.now 61 00:02:45.860 --> 00:02:47.970 and passing the timezone here directly, 62 00:02:47.970 --> 00:02:49.470 this is an alternative. 63 00:02:49.470 --> 00:02:53.343 So of course, we do have to import the datetime module, 64 00:02:54.190 --> 00:02:57.180 and the pytz module. 65 00:02:57.180 --> 00:03:00.210 These are just going up to the top and we're doing import 66 00:03:00.210 --> 00:03:02.860 pytz and import datetime. 67 00:03:02.860 --> 00:03:05.740 So there we have the current datetime in UTC, 68 00:03:05.740 --> 00:03:08.270 let's get the current timestamp in UTC, 69 00:03:08.270 --> 00:03:11.360 and that's current datetime UTC dot timestamp. 70 00:03:11.360 --> 00:03:14.240 And then we're gonna put that into the database. 71 00:03:14.240 --> 00:03:16.430 The reason I opted for putting the timestamp 72 00:03:16.430 --> 00:03:17.380 before the option ID, 73 00:03:17.380 --> 00:03:20.170 is just because I like seeing self.id there at the end. 74 00:03:20.170 --> 00:03:22.990 It seems to be not something we're doing everywhere, 75 00:03:22.990 --> 00:03:24.760 so it just makes sense to put it there. 76 00:03:24.760 --> 00:03:27.280 But it's up to you where you wanna put your parameters. 77 00:03:27.280 --> 00:03:30.240 Finally, we can display the vote dates in app.py. 78 00:03:30.240 --> 00:03:32.270 So what I'm gonna do is go down here 79 00:03:32.270 --> 00:03:33.600 to show all votes, 80 00:03:33.600 --> 00:03:35.367 and I'm gonna add a couple of lines to it. 81 00:03:35.367 --> 00:03:37.760 I'm gonna ask whether the user 82 00:03:37.760 --> 00:03:39.650 wants to view the vote log, 83 00:03:39.650 --> 00:03:40.750 so who's voted for what. 84 00:03:40.750 --> 00:03:44.310 I'm gonna say vote log equal 85 00:03:44.310 --> 00:03:48.450 input, something like would you want to see the vote log? 86 00:03:48.450 --> 00:03:51.170 And we're gonna default to no. 87 00:03:51.170 --> 00:03:52.420 Like that. 88 00:03:52.420 --> 00:03:54.830 And then, if the vote log 89 00:03:54.830 --> 00:03:56.180 is equal to yes, 90 00:03:56.180 --> 00:03:59.690 we're gonna print vote for options, 91 00:03:59.690 --> 00:04:02.550 and we're gonna pass in the options in here. 92 00:04:02.550 --> 00:04:05.810 Now we do have to create this function, so let's do that. 93 00:04:05.810 --> 00:04:06.643 I'm gonna do 94 00:04:07.630 --> 00:04:11.560 print votes for options like that. 95 00:04:11.560 --> 00:04:14.100 It's list and options list there. 96 00:04:14.100 --> 00:04:17.513 And this is gonna be a list of option. 97 00:04:18.610 --> 00:04:21.260 And what this is gonna do is go through the options 98 00:04:21.260 --> 00:04:22.710 and print out each vote 99 00:04:22.710 --> 00:04:24.390 and information about each vote. 100 00:04:24.390 --> 00:04:26.130 Basically if you wanna see who voted for what 101 00:04:26.130 --> 00:04:27.330 and when they did it, 102 00:04:27.330 --> 00:04:28.660 you print this out. 103 00:04:28.660 --> 00:04:30.980 So we'll do for option in options, 104 00:04:30.980 --> 00:04:34.050 and then I'm gonna print out the option text. 105 00:04:34.050 --> 00:04:36.500 So we'll do option.text like that. 106 00:04:36.500 --> 00:04:38.130 And then we'll do for vote 107 00:04:38.130 --> 00:04:41.159 in options., or rather options.vote. 108 00:04:41.159 --> 00:04:42.840 Then we're gonna grab the date 109 00:04:42.840 --> 00:04:44.620 and print the vote information. 110 00:04:44.620 --> 00:04:47.030 Oh by the way, this should be option.votes there 111 00:04:47.030 --> 00:04:49.260 otherwise we're trying to call the function. 112 00:04:49.260 --> 00:04:51.070 So we're gonna do naive daytime 113 00:04:51.070 --> 00:04:52.970 is what's coming from the database. 114 00:04:52.970 --> 00:04:55.597 So we'll do daytime.daytime 115 00:04:55.597 --> 00:04:58.340 UTC from timestamp 116 00:04:58.340 --> 00:05:01.010 and we'll do vote two. 117 00:05:01.010 --> 00:05:02.780 We do have to import the daytime module, 118 00:05:02.780 --> 00:05:04.280 so we'll do import this name, 119 00:05:04.280 --> 00:05:06.203 import the daytime module in there. 120 00:05:07.110 --> 00:05:09.130 Then we get the UTC date, 121 00:05:09.130 --> 00:05:12.420 which is pytz.utc.localize 122 00:05:12.420 --> 00:05:15.200 and put in the naive data. 123 00:05:15.200 --> 00:05:17.430 We do have to import the pytz module, 124 00:05:17.430 --> 00:05:19.660 so we'll do that as well. 125 00:05:19.660 --> 00:05:21.720 Now, we grab the local date, 126 00:05:21.720 --> 00:05:24.485 and that's UTC date astimezone 127 00:05:24.485 --> 00:05:26.880 and we're gonna do pytz.timezone 128 00:05:27.910 --> 00:05:29.933 Europe slash London. 129 00:05:31.060 --> 00:05:35.500 And then we're gonna do local date as a string 130 00:05:35.500 --> 00:05:37.750 is gonna be local date.strftime 131 00:05:38.810 --> 00:05:40.510 and we're gonna pass in here something like 132 00:05:40.510 --> 00:05:43.050 percent y, percent m, percent d, 133 00:05:43.050 --> 00:05:44.463 percent h, percent n. 134 00:05:45.390 --> 00:05:47.260 I'm actually okay with just calculating that 135 00:05:47.260 --> 00:05:48.093 to the end of there 136 00:05:48.093 --> 00:05:50.290 so that we get the local date as a string. 137 00:05:50.290 --> 00:05:51.860 So I'm just gonna do that instead, 138 00:05:51.860 --> 00:05:54.890 but it's up to you how far you wanna subdivide it. 139 00:05:54.890 --> 00:05:55.723 And finally at the end, 140 00:05:55.723 --> 00:05:57.740 we're gonna do printout, 141 00:05:57.740 --> 00:05:59.730 backslash d for a tab character, 142 00:05:59.730 --> 00:06:01.990 which gives us a few spaces, 143 00:06:01.990 --> 00:06:04.210 and then we'll do vote zero 144 00:06:04.210 --> 00:06:06.193 on local date. 145 00:06:07.400 --> 00:06:09.420 Something that is hard coded in here 146 00:06:09.420 --> 00:06:11.883 is of course the time zone information. 147 00:06:11.883 --> 00:06:14.280 What I would recommend when you're getting into 148 00:06:14.280 --> 00:06:16.413 this level of, you know, functionality, 149 00:06:16.413 --> 00:06:20.440 is probably to create a model for users, 150 00:06:20.440 --> 00:06:22.020 store them in their own table, 151 00:06:22.020 --> 00:06:25.280 store the timezone information alongside their data, 152 00:06:25.280 --> 00:06:27.550 and, you know, that way you can start to build out 153 00:06:27.550 --> 00:06:30.380 more functionality in this application. 154 00:06:30.380 --> 00:06:32.440 But for now, we're gonna go ahead and right click 155 00:06:32.440 --> 00:06:34.173 app.py and run it. 156 00:06:35.120 --> 00:06:36.670 I'm gonna load this from the dot m file, 157 00:06:36.670 --> 00:06:37.790 we're gonna create a poll. 158 00:06:37.790 --> 00:06:39.620 It's gonna be flash versus jango. 159 00:06:39.620 --> 00:06:42.280 Let's say poll owner is gonna be me. 160 00:06:42.280 --> 00:06:45.010 Flask and jango and it depends 161 00:06:45.010 --> 00:06:46.610 are gonna be our three options. 162 00:06:46.610 --> 00:06:48.410 And then we're gonna list the open ports, 163 00:06:48.410 --> 00:06:49.340 make sure this is working. 164 00:06:49.340 --> 00:06:50.830 You can see that it's there. 165 00:06:50.830 --> 00:06:52.080 We're gonna vote on a poll. 166 00:06:52.080 --> 00:06:53.500 That's the ID one, 167 00:06:53.500 --> 00:06:55.150 and obviously we're gonna vote for flask. 168 00:06:55.150 --> 00:06:56.763 And we're gonna vote as rolf. 169 00:06:57.640 --> 00:06:59.510 Now we're gonna show the poll votes. 170 00:06:59.510 --> 00:07:00.670 So we'll do show poll votes, 171 00:07:00.670 --> 00:07:01.770 we're gonna see poll one, 172 00:07:01.770 --> 00:07:04.080 and you can see that flask got one vote, 173 00:07:04.080 --> 00:07:05.930 and that's 100 percent of the total. 174 00:07:05.930 --> 00:07:08.250 And now we wanna see the vote log. 175 00:07:08.250 --> 00:07:10.123 So we'll press on the y here. 176 00:07:11.250 --> 00:07:16.110 And you can see that each option gets their sub menu there. 177 00:07:16.110 --> 00:07:19.440 And then here we see rolf on 2020-05-16. 178 00:07:19.440 --> 00:07:20.620 So that's today 179 00:07:20.620 --> 00:07:22.520 at 5:06. 180 00:07:22.520 --> 00:07:26.800 So two things that we've learned in this video, really. 181 00:07:26.800 --> 00:07:30.240 The first one is how to use the data and times 182 00:07:30.240 --> 00:07:32.230 from your database here in the polling application, 183 00:07:32.230 --> 00:07:33.240 which is great. 184 00:07:33.240 --> 00:07:34.930 But really the more important thing 185 00:07:34.930 --> 00:07:37.790 is how to change something in your database 186 00:07:37.790 --> 00:07:41.270 and propagate that change throughout your application. 187 00:07:41.270 --> 00:07:43.060 Usually the flow for a change like this 188 00:07:43.060 --> 00:07:46.350 is gonna start with the data you want to handle, 189 00:07:46.350 --> 00:07:49.270 or rather how you want the user to interact with it. 190 00:07:49.270 --> 00:07:51.470 So figure out the data you want to store 191 00:07:51.470 --> 00:07:53.260 and the data the users need, 192 00:07:53.260 --> 00:07:55.300 and then work backwards from the database 193 00:07:55.300 --> 00:07:56.620 to add the necessary flow. 194 00:07:56.620 --> 00:07:58.450 Change the database interaction function 195 00:07:58.450 --> 00:07:59.700 and the query. 196 00:07:59.700 --> 00:08:02.220 Change the model that's using that, 197 00:08:02.220 --> 00:08:05.188 and then change the user facing code that's using that. 198 00:08:05.188 --> 00:08:08.973 That way, you're always in a working state. 199 00:08:10.030 --> 00:08:10.900 But that's about it. 200 00:08:10.900 --> 00:08:12.750 Thank you for joining me in this section, 201 00:08:12.750 --> 00:08:13.620 I hope you have enjoyed it, 202 00:08:13.620 --> 00:08:16.270 I hope you've enjoyed learning about data and times, 203 00:08:16.270 --> 00:08:18.540 how to simplify our code, how to use models, 204 00:08:18.540 --> 00:08:21.226 and how we can create these larger python applications 205 00:08:21.226 --> 00:08:23.430 that use databases. 206 00:08:23.430 --> 00:08:24.600 Thanks guys for joining me, 207 00:08:24.600 --> 00:08:25.560 thank you for watching, 208 00:08:25.560 --> 00:08:27.210 and I'll see you in the next one.