Automatically Install Dependencies From Python Code

Key Takeaways

what is going on guys welcome back in this video today we're going to learn about the python package that allows us to automatically find all modules and packages that are used in a project and to automatically create a requirements txt file based on that so let us get right into it [Music] all right so for this video today I'm going to be working on Linux however all of this works on Windows in the same way and I assume also on Mac because the python package that we're going to use in this video is platform independent and the name of this package is PIP Rex so basically pip requirements and we can install it by saying pip 3 or pip depending on your operating system and installation install pip Rex like this in my case already installed and this package allows us to automatically create a requirements txt file based on packages and modules used in a code base so not on what we have installed so it's not like saying uh pip freeze in an environment getting all the packages and then putting this into a requirements file because first of all this includes all the packages that you have installed second of all it doesn't include packages that are being used but you don't have installed so maybe I have a project where I use most of these packages but for example I don't use uh Twisted so it would still put Twisted into the requirements file or maybe I'm using some other module that is not listed here and I still want to have it in the requirements file but I don't want to install it necessarily on my system for whatever reason we can use piprex to automatically look at the code and extract all the packages from the import statements and to then essentially create a requirements txt file based on that so we're going to use a very simple example here I'm going to create a file main.py so I'm going to just create it here I'm going to also make a directory my underscore module and I'm going to go into that module and I'm going to create a couple of files here maybe module 1.py module 2.py and module 3.py so just to complete what I was talking about here before what we usually do is we create a virtual environment we install the packages that we need we make everything compatible and then we do pip freeze and then we put that into a requirements dot txt file not tyt sorry txt and then basically you have this file requirements txt that you can just look at with all the dependencies and what we can do is we can say tip 3 install Dash R requirements txt and this basically then allows us to just install the packages that are listed in this txt file with the respective version so this is what we can do but again as I mentioned this includes modules in the environment we maybe don't want to include because we don't use them in the project and it also uh doesn't include everything that we don't have installed so let me just remove the requirements files here um and now what we're going to do is we're going to just edit the module files here we're just going to do something very simple I don't know maybe we're going to just do the Imports actually by the way so that we can actually use this we need to also create a net py file so let's go let's go into the module 1py and let's do some basic stuff for example import numpy SNP import pandas aspd and maybe you want to have some basic function my function uh it will return NP arrange zero one hundreds um one or something like that and then we're gonna have my function two or something whatever is going to just return a PD data frame based on an empty dictionary I hope this works I mean actually the code doesn't have to work uh the main focus is on the Imports because whether we use the Imports or not doesn't matter because the tool is going to look at the Imports and it's then going to create the requirements filed based on that uh so I can just close this now I can go into the module two not PX but py here we're going to import requests Maybe we're going to import beautiful or actually from you to fall Su 4 import or actually it's bs4 right from bs4 import beautiful soup like this we're not going to write any code here and module three here the interesting thing now we're going to import a module that's not installed on the system for example import chess I don't have the chess module on my system we can see that this is the case by calling pip 3 freeze we're going to grab everything where chess occurs and we don't have anything where chess occurs if I do the same thing for numpa you're going to see that it will find numpy okay so basically what I'm going to do now is I'm going to go to the main py file and I'm going to just say from my module import module one I'm going to do that three times for module two and three as well and that's now my project I'm not going to do anything with it this is just um some some sample code here and now one of the packages is not installed I have a bunch of packages installed that are not used I want to have a requirements txt file based on that um based on this code base here so what I do is I say pip Rex after I have installed it and I provide the path to the code in this case I'm already in the correct directory so I'm just going to say dot to point to this directory otherwise I could also specify the full path so home or whatever or my case since I'm on WSL it's going to be Mount C and so on but I can just go with uh with a DOT here so pip Rex Dot and what you see now is it created a requirements txt file which we shall verify manually and you can also see that here import name chess not found locally so it's resolving it with a Pi Pi server um and it found this package which is in this case the correct one same for request do I not have requests to install this interesting not sure if I have requests installed I do actually um but still it finds uh the package and what I can do here is I can open up now the requirements txt file and you can see that this is um what we need here so this is actually the requirements txt file based on the code not on my environment so chess is included here as well even though I don't have chess on my system so if I actually go ahead and say Python 3 my module uh module 3 is going to say no module named chess as you can see now if I want to change something if I want to overwrite this of course I can just delete the requirements txt file or I can just rerun the command and I can say dash dash Force to overwrite the existing requirements file and that's about it this is how you can automatically create requirements txt files based on the code not based on your environment and not based on manual specifications so that's it for today's video I hope you enjoyed it and hope you learned something if so let me know by hitting the like button and leaving a comment in the comment section down below and of course don't forget to subscribe to this Channel and hit the notification Bell to not miss a single future video for free other than that thank you much for watching see you in the next video and bye