# Installing packages

Hey there! Welcome back to the Python basics tutorial. Last time you learned about libraries and modules. Today you'll discover how to install them easily.

There's a tool called `pip` (Pip install packages) which is the most common way of installing third-party packages from PyPI (Python Packaging Index).

## Installation

### Windows

Pip is installed by default with Python on Windows. To verify, run `pip --version` in the Command Prompt.

### MacOS

Pip is also installed by default with Python by both `Homebrew` and the installer on python.org.

### Linux

On Linux, pip is usually not installed. Don't get worried, you can install it easily.

#### Ubuntu/Debian

`sudo apt-get install python3-pip`

#### Fedora

Pip is installed by default when you install the `python3` package.

#### Arch Linux

`pacman -s python-pip`

## Running Pip

Fire up your terminal emulator : Command Prompt or `cmd` on Windows, `Terminal` on Mac and Linux. 

{% hint style="info" %}
Remember, run the following commands from a terminal emulator, NOT from a Python console.
{% endhint %}

Now type in `pip --version` or `pip3 --version` in MacOS/Linux to verify pip installation. Now, we can install a popular library called `numpy` which is used for mathematical stuff. To install packages with `pip`:

```bash
pip install <package_name>
```

So, to install `numpy` we will do:

```bash
pip install numpy
```

If you run the command in your terminal, you'll see something like this:

```bash
$ pip install numpy
Collecting numpy
  Using cached https://files.pythonhosted.org/packages/ff/7f/9d804d2348471c67a7d8b5f84f9bc59fd1cefa148986f2b74552f8573555/numpy-1.15.4-cp36-cp36m-manylinux1_x86_64.whl
Installing collected packages: numpy
Successfully installed numpy-1.15.4
```

You may see a progress bar too.

That's all to installing packages. You can simply open up a Python file now and `import numpy` and use it.

{% hint style="info" %}
There's also another tool named `easy_install` but we'll be using Pip in these tutorials.
{% endhint %}

## Troubleshooting

If you get an error `'Pip' is not recognized as a command.` or something similar, you can follow the steps below, or skip to the last section "get-pip.py".

### Windows

#### Reinstall Python

If you did not check the box `Add Python to PATH` box during installation, you can reinstall Python again and make sure to check the box this time.

#### Add Python to PATH

To configure your current installation:

Open the Python console and type in these commands:

```python
>>> import os
>>> import sys
>>> os.path.dirname(sys.executable)
```

This will return a location or a path. Copy this.

&#x20;Now go to `System Properties -> Advanced`, or just press Windows Key + Pause. Then click "Environment Variables". Create a new "System Variable" called `PYTHON_HOME` and set the value to the path you just copied. Then find another "System Variable" called PATH, click Edit, and add this to the end: `;%PYTHON_HOME%\;%PYTHON_HOME%\Scripts\`. and save. Now open up a new command prompt and type in `pip --version` again. It should work now.

### MacOS/Linux

First of all, check if you're actually running `pip3` or `pip` . If it's `pip`, try again with `pip3`. If none of them work:

Try `sudo easy_install pip`, or try `brew install python3` again on MacOS. On Linux, try `sudo apt-get install python3-pip`.

### get-pip.py

If none of the solutions above work, you can try using `get-pip.py`. Download it from <https://bootstrap.pypa.io/get-pip.py> , open up the terminal/Command Prompt, navigate to the file and do `python get-pip.py` on Windows and `python3 get-pip.py` on MacOS/Linux. This should fix it. If not, Google is your friend!