add in pixi and uv commands

Author: munkm

content/how-tos/envs.md renamed to content/how-tos/how-to-create-environments.md

@@ -43,7 +43,7 @@ environments, testing environments, or the project itself). You can install the
 with pip in your venv using: 
 
 ```
-pip install -r requirements.txt
+pip install -r <path/to/requirements.txt>
 ```
 
 Remember to re-activate your environment every time you open a new terminal, using:
@@ -52,7 +52,7 @@ Remember to re-activate your environment every time you open a new terminal, usi
 source science/bin/activate
 ```
 
-### Set up a virtual environment using conda 
+### Set up an environment using conda 
 
 With conda, we can create a new environment named science (-n is the same as passing --name):
 
@@ -73,12 +73,12 @@ For example:
 conda install ipython numpy scipy
 ```
 
-Often you'll interact with projects that have a specific list of dependencies (for development 
-environments, testing environments, or the project itself). You can install the list of dependencies
-with conda in your environment using: 
+Some projects distribute environment files with listed dependencies with an `environment.yml` file. 
+The first line of this file sets the environment's name. To
+create an environment and install the dependencies with this file, use: 
 
 ```
-conda install --file requirements.txt
+conda env create -f <path/to/environment.yml>
 ```
 
 Remember to re-activate your environment every time you open a new terminal:
@@ -87,7 +87,7 @@ Remember to re-activate your environment every time you open a new terminal:
 conda activate science
 ```
 
-### Set up a virtual environment using mamba 
+### Set up an environment using mamba 
 
 With mamba, like conda, we can create a new environment named science (-n is the same as passing --name):
 
@@ -108,16 +108,94 @@ For example:
 mamba install ipython numpy scipy
 ```
 
-Often you'll interact with projects that have a specific list of dependencies (for development 
-environments, testing environments, or the project itself). You can install the list of dependencies
-with mamba in your environment using: 
+To install a specific environment from a `.yml` file, use: 
 
 ```
-mamba install --file requirements.txt
+mamba create -f </path/to/environment.yml>
 ```
 
 Remember to re-activate your environment every time you open a new terminal:
 
 ```
 mamba activate science
 ```
+
+### Set up a virtual environment using uv 
+
+To create a new environment using uv in our project folder called `science`:  
+
+```
+uv venv
+```
+
+Start using your environment by activating it: 
+
+```
+source .venv/bin/activate
+```
+
+You are now ready to install Scientific Python packages using `uv`!
+For example:
+
+```
+uv pip install ipython numpy scipy
+```
+
+To install dependencies from a requirements file, use: 
+
+```
+uv pip install -f </path/to/requirements.txt>
+```
+
+Remember to re-activate your environment time you open a new terminal:
+
+```
+source <path/to/science/>.venv/bin/activate
+```
+
+You can find more information on using uv for environments 
+[here](https://docs.astral.sh/uv/pip/environments/#creating-a-virtual-environment).
+
+### Set up a virtual environment using pixi 
+
+To initialize a new project with pixi in our project called `science`, execute:   
+
+```
+pixi init 
+```
+
+You are now ready to install Scientific Python packages as dependencies in this project!
+From the science directory, execute:
+
+```
+pixi add ipython numpy scipy
+```
+
+To install dependencies from a file like `environment.yml`, use: 
+
+```
+pixi init --import <path/to/environment.yml>
+```
+
+Remember to re-activate your environment when you re-open a terminal. Navigate to 
+the science folder, and execute:
+
+```
+pixi shell 
+```
+
+A pixi project may have multiple environments defined in the `pixi.toml` file. To 
+load a specific environment: 
+
+```
+pixi shell --environment=<envname> 
+```
+
+You can find more information on using pixi  
+[here](https://docs.astral.sh/uv/pip/environments/#creating-a-virtual-environment).
+
+
+
+
+
+