We recommend using the latest version of Python 3, LibLET is tested under Python 3.7 and newer. These packages (and the related dependencies) will be installed automatically when installing LibLET:

Virtual environments

It’s suggested to use a virtual environment to manage Python dependencies: virtual environments are independent groups of Python libraries, one for each project; packages installed for one project will not affect other projects or the operating system’s packages.

Create an environment

Python 3 comes bundled with the venv module to create virtual environments. Create a project folder and a venv folder within:

$ mkdir myproject
$ cd myproject
$ python3 -m venv venv

On Windows:

$ py -3 -m venv venv

Activate the environment

Every time you decide to use the library, activate the environment:

$ . venv/bin/activate

On Windows:

> venv\Scripts\activate

Install the library

Within the activated environment, use the following command to install the library:

$ pip install liblet

Install the external dependencies

To use LibLET you also need to manually install:

  • the Graphviz visualization software,

  • the ANTLR Tool, that is antlr-4.7.2-complete.jar, and

  • the LLVM toolchain in case you want to use the LLVM helper class (present code is tested with version 10 of the toolchain).

Follow the installation instruction on the Graphviz and LLVM sites according to your operating system and package manager.

To install the ANTLR Tool, you can use the install_antlrjar command provided by LibLET as:

$ install_antlrjar

and set the ANTLR4_JAR environment variable to the full path of the downloaded jar as advised. Finally, if you plan to use the LLVM helper class, set the LLVM_VERSION environment variable to the installed toolchain version.