# Setting up Environments 🌲

## Why Environments are Necessary

The main purpose of using environments is to create a segregation between the dependencies of different python projects. It eliminates (at least tries to) dependency conflicts since each project has it's own set of dependencies, isolated from one another.

Suppose you are working on two projects, `Project_1` and `Project_2`, both of which have a dependency on the same library, let's say the awesome `Requests` library. Dependency conflict will arise, if for some reason, the two projects need different versions of `Request` library. For example, maybe `Project_1` needs `v1.0.0`, while `Project_2` requires the newer `v2.0.0`.

This can easily be avoided by using individual environment for each project where all the dependencies of the corresponding project will reside. There are multiple ways you can create environment. We'll mainly focus on creating python3 based `conda environment` and native `virtual environment`.


## Conda Environment

### Installing Anaconda Distribution
Install anaconda on your machine. I personally prefer miniconda over the full fledged anaconda. The installation guide can be found here:
* [Linux](https://docs.anaconda.com/anaconda/install/linux/)
* [MacOS](https://docs.anaconda.com/anaconda/install/mac-os/)

### Creating Conda Environment
 After installing anaconda, to create a python3 environment with a specific version of python, type the following command. This will create an environemnt named `myenv` with python 3.7:

```bash
$ conda create -n myenv python=3.7
```

### Activating Conda Environment
 After creating the conda environment, type the folling command to activate the `myenv` environment:
```bash
$ conda activate myenv
```

### Deactivating Conda Environment
To deactivate, simply type:
```bash
$ conda deactivate
```


## Virtual Environment

### Installing python3-venv
To create virtual environment, first you need to install `python3-venv`. Run:

```
$ sudo apt update
$ sudo apt-get install python3-venv
```

### Creating Virtual Environments
Create a virtual environment named `myenv` via running:
```bash
$ python3 -m venv myenv
```
You should see a folder named `myenv` in your current directory. This is the folder where all your project-specific dependencies are going to reside.

### Activating Virtual Environments
To activate `myenv`, run:
```bash
$ source myenv/bin/activate
```

### Deactivating Virtual Environment
To deactivate, simply type:
```bash
$ deactivate
```

## Selecting & Switching Between the Environments in VS Code

* Press `ctrl+shift+P` to open VS Code's `command palette`. You should be seeing something like this:

    ![Imgur](https://imgur.com/ZVtW5Sw.png)


* Type `interpreter` in the search box. And select the `Python: Select Interpreter` option. You should see a list of all the available (both conda and virtual environments are shown) python environments. You should also see your recently created `myenv` environment there. Toggle and select your environment and you are good to go.

    ![Imgur](https://imgur.com/PW47gQS.png)

## Installing Third Party Packages
To install third party packages/libraries/moduels from `pip` or `conda`,
* Activate your respective environments
* Depending on the package manager you want to use, type either:

```bash
$ pip install <package_name>
```
or
```bash
conda install <package_name>
```
![Imgur](https://imgur.com/Hv5aRxh.png)