Installing silx in a virtualenv

This step-by-step guide explains how to install silx in a virtualenv.

Prerequisites

This guide assumes that your system meets the following requirements:

  • a version of python compatible with silx is installed (Python >= 3.5)
  • the pip installer for python packages is installed

Installation procedure

Create a virtualenv

The files required by a virtual environment are created in a new folder with the same name as the virtualenv. So make sure you are in a directory in which you have write permissions.

In this tutorial we use a folder venvs in our home directory, and we create a virtual environment named silx_venv

cd
mkdir -p venvs
cd venvs
python -m venv silx_venv

A virtualenv contains a copy of your default python interpreter with a few tools to install packages (pip, setuptools).

Virtual environments are created using a builtin standard library, venv (Python3 only):

python3 -m venv /path/to/new/virtual/environment

Note

On Debian platforms, you might need to install the python3-venv package.

If you don’t need to start with a clean environment and you don’t want to install each required library one by one, you can use a command line option to create a virtualenv with access to all system packages: --system-site-packages

To use a different python interpreter, use it to create the virtual environment. For example, to use python 3.5:

/usr/bin/python3.5 -m venv silx_venv

Activate a virtualenv

A script is provided in your virtualenv to activate it.

source silx_venv/bin/activate

After activating your new virtualenv, this python interpreter and its package tools are used, instead of the ones from the system.

Any libraries you will install or upgrade will be inside the virtual environment, and will not affect the rest of system.

To deactivate the virtual environment, just type deactivate.

Upgrade pip

After activating silx_venv, you should upgrade pip:

python -m pip install --upgrade pip

Upgrade setuptools and wheel

Upgrading the python packaging related libraries can make installing the rest of the libraries much easier.

pip install setuptools --upgrade
pip install wheel --upgrade

Install build dependencies

The following command installs libraries that are required to build and install silx:

pip install numpy cython

Install silx

To install silx with minimal dependencies, run:

pip install silx

To install silx with all dependencies, run:

pip install silx[full]

To test silx, open an interactive python console:

python

If you don’t have PyQt5 or PySide2, run:

WITH_QT_TEST=False python

Run the test suite using:

>>> import silx.test
>>> silx.test.run_tests()