🐍 Python prompt to load venv in 13 lines of .bashrc

Hey there. We have been having fun with making our own prompts. That's right. You don't need almost Zshell to make your own pretty prompts. And one of the things I hate the most about Python is Python virtual environments. And so we made it do this. So right now I'm just in my normal prompt and I want to go into a directory that has Oh, look at that. It's a directory that has avn uh you know sub uh whatever you want to call it uh subdirectory there. And so then we're going to accept it. We say yeah I want to use that. And so we say enter. And then now from now on it tells us we have a thing. And even if we go back to wherever we were when we come back there we get a cool little Python that tells us we're in a Python virtual environment and that it has been loaded. And you can do which Python. you can see which Python is there and and all of that. So, how do we make that? It's actually pretty easy. Um, once you have your own function for making your own prompt and why don't you? It's not that hard. Uh, you can do PS1 like this and you can control it and then you can use you can use the the very powerful bash prompt command which runs any that runs this every single time your prompt runs. And so we can put the LENV function inside of that which we'll now go over a little bit. So the first thing we do is we look to see if there is a vital Python virtual environment. Then we check to see if it's on. It's already been turned on which means that we are you know that Python is in av Python. That's what this is doing. This is a regular expression check to sell to checks to see if this is at the end of the string that which Python shows us where we're at. We declare a benv's hash. This is only in bash I think 3.5 and big above which are key value pairs kind of like reddus if you know what it is. Uh and ll this is found this says do did we find it? If we found one then go ahead and return. We already know what we're doing. If we have a virtual environment now go ahead and return. Um or sorry if we found one uh we either found a virtual environment or return. That means we're in a directory that doesn't even have in it. Okay. And when we get down here and we see, okay, did I already ask the question about whether it should be used or not? Okay, so that's what it's saying. It's saying, look, if I never even asked the question before, or if I have already asked the question and I cached the answer in this shell, then I'm going to go keep it, right? So then we say, okay, if we get this far, it's like I don't I haven't asked the question, so I'm going to go ahead and ask put the answer and answer. This drops the case. This is a lower pre lower case. Do you guys see a bug? What bug do you see? And then we check to see if the answer is empty. And if uh I mean if the answer if the answer is empty then the default answer becomes yes. So that you can just push enter and it gets accepted as yeah. Uh and so here we go. So then we go we add for our current directory and current working directory. We'll go ahead and add the answer in this case Y. And then we check to see if the beginning of the answer is Y. And if it is then we run the activate script. And as soon as it's activated, every time the prompt runs, uh, we added a line to the prompt that says we check the cache every time the prompt runs and say, hey, do I have an entry and was the entry yes for this directory? And if so, we change our dollar dollar, you know, our dollar uh, prompt into a Python. And so that gives us the opportunity to go to see that we're in a Python virtual environment that's already been loaded. and it helps you annoy just one of the many things that are annoying about Python. But hopefully that helps. Bye.

The simplest way to remember to load a python virtual environment without all the bloat. #python #programming #bash