# Minimalist Installation

## A minimalist approach: `conda` (recommended for long-term learning)

If you want a more minimalist installation that *only* includes the barebones (that can be extended) of what's needed in this context, and/or you are not running Windows 10 Pro, macOS or Linux, the recommended approach is to do a `conda` installation. This route will install a Python distribution natively with the libraries we will need. Please note that no interactive extensions or R packages are installed in this case, and also be aware the installation is less stable as it relies on the specific versions for your OS and latest releases. In most cases, it should be fine, and this particular stack is regularly tested, but some failures nevertheless happen sometimes.

To install Python and required libraries through this approach, please follow these steps:

- Install `miniconda` for your OS version from the [official link](https://docs.conda.io/en/latest/miniconda.html). Make sure to install the Python 3 (e.g. 3.9) version, not Python 2.

```{attention}
*To download Miniconda, follow these steps :*

1. Head over to the [Download Page](https://docs.conda.io/en/latest/miniconda.html) and select Python 3.9:

![Python 3.9](figs/chp4/Picture10.png)

2. We are using **Python 3.9**, so depending on which windows version you are using (32-bit or 64-bit), click on the relevant file in the Python 3.9 section (highlighted in red).
3. This will download the Miniconda installation file. Depending on your setup and browser, you will need to select where to place it (the Desktop folder would be a good option) or it will go straight into a default location (e.g. the Downloads folder)
```

- Once you have miniconda installed, we need to set up an independent virtual environment that isolates all the functionality we need.

But first, **what are environments and do you need them?**

Environments in Python are like sandboxes that have different versions of Python and/or packages installed in them. You can create, export, list, remove, and update environments. Switching or moving between environments is called activating the environment. When you are done with an environment, you may deactivate it.

For this course, we want to have a bit more control on the packages that will be installed with the environment so we will create an environment with a so-called YAML file called [`install_gds_stack.yml`](../resources/install_gds_stack.zip).

To learn more about virtual environments, you can also go [here](environment.md).

### Creating an environment from an environment.yml file

Open up a terminal as follows depending on your OS:
* "Anaconda Command Prompt" in Windows
* "Applications --> Utilities --> Terminal" in macOS
* "ctr+alt+T" in Linux


Now run the following commands:

- Get the installer file from [here](../resources/install_gds_stack.zip) and unzip it.
- Navigate to the folder where this file is (e.g. Downloads):

    ```shell
    cd /path/to/Downloads
    ```

- Execute the following command (note you will need a good and stable internet connection and will take a while to complete):

    ```shell
    conda env create -f install_gds_stack.yml
    ```

```{tip}
Depending on the speed of your connection, this step will take a while (but no less than 15-20 minutes). Grab a *cuppa* and be patient!
```

- This has created the `gds` environment, congratulations! We are _almost_ there. Now we need to _activate_ the environment. For this, run the following command:

    ```shell
    conda activate gds
    ```

    You should see the name of the environment at the start of your command prompt in parenthesis.

- Verify that the new environment was installed correctly:

    ```shell
    conda list
    ```

```{note}
This command will give you a list of the packages installed in this environment. For managing your environment or learning more about what environments are capable of, go to [Manage conda environments](https://docs.conda.io/projects/conda/en/latest/user-guide/tasks/manage-environments.html).
```

- Now we have to install the environment `gds` as a kernel on jupyter lab so you can use the packages inside it,

    ```shell
    ipython kernel install --name "gds" --user
    ```

- Once the kernel is installed and environment is activated as we did above, we can open a jupyter lab instance using the following command,

    ```shell
    jupyter lab
    ```