1 00:00:00,060 --> 00:00:06,270 Welcome to this lecture! We are done with sqlite3 so I hope you were able to build 2 00:00:06,270 --> 00:00:11,340 this script that I showed you throughout the previous lectures because in 3 00:00:11,340 --> 00:00:16,289 this lecture we are going to use the script but I'll modify it, so that it is 4 00:00:16,289 --> 00:00:22,439 compatible, interactive with PostgreSQL databases so luckily most of 5 00:00:22,439 --> 00:00:27,330 the code is the same with other with some slight changes. Of course we would need 6 00:00:27,330 --> 00:00:36,000 another library called psycopg2 and then we will grab methods from that library 7 00:00:36,000 --> 00:00:42,510 and unlike sqlite3 psycopg2 needs to be installed, so it's a third-party 8 00:00:42,510 --> 00:00:49,200 library, it don't come as sub built-in Python library, so you need psycho PG 2 9 00:00:49,200 --> 00:00:54,750 installed and you also need PostgreSQL installed in your computer. So in this 10 00:00:54,750 --> 00:00:59,760 lecture I would like to show you how to install PostgreSQL and psycopg2 as well. 11 00:00:59,760 --> 00:01:07,890 Alright, this is the official web page of PostgreSQL and you can just go 12 00:01:07,890 --> 00:01:16,890 to downloads, just here or down here, and then you want to find your operating system, 13 00:01:16,890 --> 00:01:22,369 so PostgreSQL works on Mac, Linux and Windows. 14 00:01:22,369 --> 00:01:29,310 Solaris as well. So I'm on Windows. I'll just click on windows and when you 15 00:01:29,310 --> 00:01:33,960 install PostgreSQL you are also installing the pgAdmin3 which is 16 00:01:33,960 --> 00:01:39,750 a graphical tool where you can see your databases. If you're familiar with MySQL, 17 00:01:39,750 --> 00:01:46,890 pgAdmin is equivalent to PHPMyAdmin. POstgreSQL also comes with a Stack 18 00:01:46,890 --> 00:01:51,950 Builder which is a package that you can use to download and install other 19 00:01:51,950 --> 00:01:58,380 extensions, PostgreSQL extensions, so let's say you want an extension for spatial 20 00:01:58,380 --> 00:02:03,180 data so to store spatial data in PostgreSQL so that you can use it for GIS 21 00:02:03,180 --> 00:02:07,320 applications, so that's an extension for that called PostGIS. 22 00:02:07,320 --> 00:02:12,720 So anyway I'll show you to install extensions. First you need to 23 00:02:12,720 --> 00:02:24,689 download PostgreSQL and I am on a Windows so I would click this and I'll wait a while 24 00:02:24,689 --> 00:02:27,500 until my download finishes. So I'll quickly go through the 25 00:02:29,800 --> 00:02:39,730 installation process. So I'm just being asked where I want to install PostgreSQL 26 00:02:39,730 --> 00:02:44,500 and where my data will be stored and here it should be careful with this 27 00:02:44,500 --> 00:02:50,890 credentials so your Super User, the ones who have most of the privileges to your 28 00:02:50,890 --> 00:03:00,580 databases and your super user name is Postgres and I'd actually like to create 29 00:03:00,580 --> 00:03:12,300 a simple file, a text file just to store my credentials. I would like to say the 30 00:03:21,250 --> 00:03:26,620 password as well. One, two, three, all right. So I'll enter 31 00:03:26,620 --> 00:03:33,269 postgres1234 password. Next and this is the port of your 32 00:03:38,350 --> 00:03:49,620 server, of your database server so I'd want to take a note of this too. 33 00:03:52,370 --> 00:04:01,260 This is a about your local settings so I'll just leave this default and you'll just 34 00:04:01,260 --> 00:04:16,590 have to wait a while until the isolation finishes. All right, that was successful. 35 00:04:16,590 --> 00:04:21,539 Now if you want to launch Stack Builder to install extensions for the PostgreSQL 36 00:04:21,539 --> 00:04:29,820 database, you may want to have this checked. So this is my database server 37 00:04:29,820 --> 00:04:36,479 and here you have a bunch of extensions that you may want to install. 38 00:04:36,479 --> 00:04:43,800 For example spatial extensions and you have PostGIS for 32-bit 39 00:04:43,800 --> 00:04:50,220 and PostGIS for 64-bit. If I click Next this tells me that 40 00:04:46,729 --> 00:04:52,830 If I click Next this tells me that I need one package at least to be 41 00:04:52,830 --> 00:05:05,099 installed, so let me just install PostGIS. All right, I agreed to the PostGIS license and 42 00:05:05,099 --> 00:05:09,440 then just go next. This is asking me about Gdal which is 43 00:05:14,250 --> 00:05:21,900 another interface for GIS data. All right that was how to install external 44 00:05:21,900 --> 00:05:28,590 extensions. If you want to go back to Stack Builder later your Stack Builder 45 00:05:28,590 --> 00:05:34,460 should be here or you can just go to PostgreSQL and here you have pgAdmin 46 00:05:39,449 --> 00:05:44,400 as well and here is the application Stack Builder. Alright, but if you want to work 47 00:05:44,400 --> 00:05:48,960 with Python you want to access the PostgreSQL databases through Python so 48 00:05:48,960 --> 00:05:53,639 you don't have to interact with these applications here. The way to interact 49 00:05:53,639 --> 00:06:00,539 with PostgreSQL with Python is by installing psycopg2 and you can 50 00:06:00,539 --> 00:06:06,349 install psycopg2 with pip. However you may run into problems 51 00:06:09,320 --> 00:06:16,710 because psycopg2 is written in C so you need C compiler installed in your 52 00:06:16,710 --> 00:06:23,190 system on Windows at least. You will not have this problem on a Mac and Linux. 53 00:06:23,190 --> 00:06:29,040 I am quite sure. The solution to this? Actually there are a few solutions. 54 00:06:29,040 --> 00:06:34,320 One of the solutions is that you may want to install visual studio on your Windows 55 00:06:34,320 --> 00:06:40,110 machine, but that's quite a big programs and I wouldn't want to install that, so the 56 00:06:40,110 --> 00:06:47,780 second solution which I prefer the most is to use precompiled Python libraries. 57 00:06:48,380 --> 00:06:57,060 And you can find almost any Python libraries that require C compiler you 58 00:06:57,060 --> 00:07:02,700 can find those libraries in this page served by Christoph Goblke, so we're 59 00:07:02,700 --> 00:07:14,160 looking for psycopg2. Here you have the whl files, so a whl file is a 60 00:07:14,160 --> 00:07:18,450 file that can be installed with pip so what you do when you install something 61 00:07:18,450 --> 00:07:24,720 with pip, pip install psycopg2, pip is downloading the whl file from the 62 00:07:24,720 --> 00:07:30,030 remote server and then it installs it in your system, so here you can look for 63 00:07:30,030 --> 00:07:36,740 your version and this would be the file for my system. 64 00:07:43,970 --> 00:07:51,720 So I'll just get this from here and paste it in here so that I can access it from the 65 00:07:51,720 --> 00:07:58,080 Atom command line, so here is the file that I just downloaded so just go ahead 66 00:07:58,080 --> 00:08:06,150 and pip install and then you will need to point to the whl file, 67 00:08:06,150 --> 00:08:09,140 so dot whl, alright. And that was successfully installed. I can 68 00:08:14,250 --> 00:08:27,180 quickly check if that is available and it seems to be working. You can also 69 00:08:27,180 --> 00:08:31,880 check the version of your library if you want, so it's 2.6.1. 70 00:08:31,880 --> 00:08:37,919 Alright so in the next lecture we will connect to the database to the postgreSQL 71 00:08:37,919 --> 00:08:42,870 database and then we'll be creating tables and inserting data, viewing 72 00:08:42,870 --> 00:08:48,020 deleting and updating them. So let's move on.