# How to Install IPython in VirtualEnv 'Updated for Python 3'

IPython is a powerful, interactive shell that provides an excellent alternative to the standard Python interpreter. However, installing it can sometimes be challenging, especially when working within a virtual environment (virtualenv) on Ubuntu-based systems like Ubuntu and Linux Mint.

In this article, we'll walk you through step-by-step instructions on how to install IPython in your virtualenv using pip3, which is the recommended package manager for Python 3. We will also cover some common issues that may arise during installation.

## Prerequisites

Before proceeding with these steps:

1. Make sure you have a recent version of Ubuntu or Linux Mint (14.x or later) installed on your system.

2. You should be familiar with basic terminal commands, including navigation and package management using apt-get or its alternatives like snap for newer systems.

3. IPython requires Python 3 to work properly; ensure that you're running an appropriate version.

## Step-by-step Installation Guide

### 1. Install virtualenv (if not already installed)

If you haven't installed virtualenv yet, open your terminal and run the following command:

```bash

sudo apt-get update && sudo apt-get install python3-virtualenv -y

```

### 2. Create a new virtual environment for IPython

Navigate to an empty directory where you want to create your virtual environment (we'll call it `ipython-env`):

```bash

cd ~/

mkdir ipython_envs

cd ipython_envs

virtualenv --python=python3 -m ipykernel ipython3-venv

```

### 3. Activate the newly created virtual environment

To activate your new IPython environment, use one of these commands depending on whether you're using Bash or Fish shell:

Bash/compatible shells:

```bash

source ./ipython3-venv/bin/activate

```

Fish shell:

```fish

. ~/ipython_envs/ipython3-venv/bin/ activate.fish

```

### 4. Install IPython and other required packages

Now that you're inside your virtual environment, install the necessary packages using pip:

```bash

pip3 install ipykernel pyzmq -U --upgrade-strategy=never

python -m ipykernel install --user --name='ipython3' --display='IPython'

```

### 5. (Optional) Install IPython notebook for Jupyter support

If you want to use the IPython Notebook interface with Jupyter, run:

```bash

pip3 install jupyter nb_conda_kernels ipykernel -U --upgrade-strategy=never && conda config --add PATH/envs/anaconda2/bin --prefix=/usr/local --force-reinstall

```

### 6. Start IPython

You're all set! You can now start IPython from within your virtual environment by running:

```bash

ipython3 -c 'import ipykernel; kernel = ipykernel.kernel.inprocess.get_kernel(); kernel.display_name='IPython''

```

## Troubleshooting Common Issues

### 1. pip installation fails with ZMQ version mismatch warnings

If you encounter an error like this during `pip install`:

Warning: Detected ZMQ version: 4.0.5, but pyzmq targets ZMQ 4.0.6.

Try updating the system's packages and then reinstalling IPython using pip3:

```bash

sudo apt-get update && sudo apt-get upgrade -y

```

### 2. virtualenv or IPython installation fails due to missing dependencies

Make sure you have all required development libraries installed before proceeding with these steps. You can check for any missing packages by running `apt-cache search ` in your terminal.

If the above solutions don't resolve your issues, feel free to ask for further assistance in the comments below!

How to install ipython in virtualenv