What is the project about?

PEX is a library and tool for creating self-contained, executable Python environments (.pex files) similar to virtualenvs. These .pex files can be easily distributed and run on different systems.

What problem does it solve?

PEX simplifies the deployment of Python applications. It eliminates the need for complex setup scripts or managing dependencies on target machines. It packages an application and its dependencies into a single executable file, making deployment as simple as copying the file. It also addresses portability issues by allowing a single .pex file to contain multiple platform-specific Python distributions.

What are the features of the project?

• Creates self-contained executables: Packages Python code and dependencies into a single .pex file.
• Virtualenv-like environments: Provides isolated environments, similar to virtualenv, but executable.
• Multi-platform support: Can bundle multiple Python distributions for different platforms (e.g., Linux, macOS).
• Dependency management: Handles dependencies specified via requirements files or direct package names.
• Entry point support: Allows specifying entry points (console scripts) for direct execution.
• Interpreter specification: Enables building .pex files for specific Python interpreters (e.g., PyPy).
• Ephemeral environments: Supports creating temporary environments for quick experimentation.
• Integration with build systems: Integrates with build tools like Pants, Buck, and {py}gradle.
• Tox integration: Easily integrates with tox for packaging and testing.

What are the technologies used in the project?

• Python: The core language of the project and the target language for the generated executables.
• pip: Used for dependency resolution and installation.
• tox: Used for test automation and development workflow.
• PEP 441: Based on the ideas of PEP 441 (Python Executable Zip Files).

What are the benefits of the project?

• Simplified deployment: Reduces deployment complexity to a simple file copy.
• Portability: Applications can run on different systems without dependency conflicts.
• Reproducibility: Ensures consistent environments across development, testing, and production.
• Isolation: Prevents conflicts between different applications and their dependencies.
• Faster startup: Can be faster than setting up a virtualenv, especially for large projects.
• Easy experimentation: Ephemeral environments make it easy to try out new libraries or code snippets.

What are the use cases of the project?

• Deploying Python applications: Packaging applications for distribution to servers or end-users.
• Creating command-line tools: Building self-contained CLI tools.
• Running scripts with specific dependencies: Ensuring scripts run in a consistent environment.
• Experimenting with different Python versions or libraries: Quickly testing code with different configurations.
• Distributing Python-based tools to users without Python installed: Users only need the .pex file.
• Replacing shell scripts with Python: Provides a more robust and maintainable alternative to complex shell scripts.
• Testing: Creating isolated test environments.