add new entry about Nix

content/post/2023-11-13 Nix recipe for python projects.md

@@ -0,0 +1,58 @@
+---
+date: '2023-11-13T18:21:46+01:00'
+title: 'Nix Recipe for Python Projects'
+---
+
+
+This is a quick and easy recipe to add a `default.nix` to any Python project with a `requirements.txt` file:
+
+
+```nix
+with import <nixpkgs> { };
+
+let
+  pythonPackages = python311Packages;
+in pkgs.mkShell rec {
+  name = "impurePythonEnv";
+  venvDir = "./.venv";
+  buildInputs = [
+    # A python interpreter including the 'venv' module is required to bootstrap
+    # the environment.
+    pythonPackages.python
+
+    # This execute some shell code to initialize a venv in $venvDir before
+    # dropping into the shell
+    pythonPackages.venvShellHook
+
+    # Those are dependencies that we would like to use from nixpkgs, which will
+    # add them to PYTHONPATH and thus make them accessible from within the venv.
+    pythonPackages.numpy
+    pythonPackages.requests
+
+    # In this particular example, in order to compile any binary extensions they may
+    # require, the python modules listed in the hypothetical requirements.txt need
+    # the following packages to be installed locally:
+    taglib
+    openssl
+    git
+    libxml2
+    libxslt
+    libzip
+    zlib
+  ];
+
+  # Now we can execute any commands within the virtual environment.
+  # This is optional and can be left out to run pip manually.
+  postShellHook = ''
+    pip install -r requirements.txt
+  '';
+
+}
+```
+
+
+Now, you will get a clean environment by running:
+
+```
+nix-shell
+```