Python Language Support

Glass provides comprehensive Python support with automatic virtual environment detection, multiple LSP server options, and extensive test framework integration.

LSP Servers

Glass supports multiple Python language servers:

Basedpyright (Default)
Pyright
Ty (Experimental)
Ruff (Linter)

A faster fork of Pyright with improved performance:

Full type checking
Intelligent completions
Go-to-definition and references
Automatic import suggestions
Inlay hints for types

Installed automatically from npm.

Microsoft’s official Python language server:

{
  "languages": {
    "Python": {
      "language_servers": ["pyright", "..."]
    }
  }
}

Same features as Basedpyright, official Microsoft implementation.

A modern Python language server written in Rust:

{
  "languages": {
    "Python": {
      "language_servers": ["ty", "..."]
    }
  }
}

Features:

Extremely fast
Low memory usage
Downloaded from astral-sh/ty releases

Virtual Environment Detection

Glass automatically detects and uses Python virtual environments:

Detection Methods

Project-local Environments
Global Environments
Custom Paths

Glass detects these virtual environments automatically:

venv: Standard library python -m venv
virtualenv: Third-party tool
Poetry: poetry install environments
Pipenv: pipenv install environments
uv: Modern Python package manager
Conda/Mamba: Anaconda environments
Pixi: Modern package manager

Priority order (most specific first):

UV workspace environments
UV project environments
Poetry environments
Pipenv environments
venv/virtualenv
Conda environments

System Python installations:

Pyenv: Pyenv-managed Pythons
Homebrew: Homebrew Python (macOS)
System: /usr/bin/python3
Windows Store: Windows Store Python
Python.org: Official installers (macOS)

Global environments are used only if no project-local environment is found.

Environment Priority

For workspaces with multiple packages:

project/
├── .venv              # Root environment
├── backend/
│   └── .venv          # Backend environment (higher priority)
└── frontend/
    └── node_modules/

Glass prefers the environment closest to the current file:

Same directory as file
Parent directories (closest first)
Workspace root

Glass uses Python Environment Tools (PET) for environment detection, the same library used by VS Code.

Features

Intelligent Completions

Methods & Functions
Import Suggestions
Type Hints

data = [1, 2, 3]
data.| # Shows list methods with signatures

Completions include:

Method signatures with parameter types
Return type annotations
Docstrings

from pathlib import |

Auto-completes:

Available exports
Type-only imports
Sub-modules

Glass sorts completions by visibility:

Public members (no underscore)
Protected members (_name)
Private members (__name)
Dunder methods (__init__, etc.)

def process(data: list[str]) -> dict[str, int]:
    result = {}  # Glass infers type: dict[str, int]
    for item in data:  # item inferred as str
        result[item] = len(item)
    return result

Hover over variables to see inferred types.

Custom Completion Sorting

Glass customizes Pyright’s completion order:

class MyClass:
    public_field: str         # Priority 0 (public)
    _protected_field: int     # Priority 1 (protected)
    __private_field: bool     # Priority 2 (private)
    __init__(self):           # Priority 3 (dunder)
        pass

Within each visibility level, items are sorted by kind:

Enum members
Fields
Properties
Variables
Constants
Methods/Functions
Classes
Modules

Test Framework Integration

Glass provides built-in support for Python test frameworks:

Test Runner Selection

Configure your preferred test runner:

{
  "languages": {
    "Python": {
      "tasks": {
        "variables": {
          "TEST_RUNNER": "pytest"  // or "unittest"
        }
      }
    }
  }
}

pytest (Default)

File Tests
Class Tests
Single Test

Run all tests in a file:

python3 -m pytest test_example.py

Glass automatically uses the active virtual environment’s Python.

class TestExample:  # ← Click to run all tests in class
    def test_one(self):
        assert True
    
    def test_two(self):
        assert True

Command:

python3 -m pytest test_example.py::TestExample

def test_specific():  # ← Click to run this test
    assert 2 + 2 == 4

Command:

python3 -m pytest test_example.py::test_specific

unittest (Standard Library)

File Tests
Class Tests
Single Test

python3 -m unittest tests/test_example.py

class TestCalculator(unittest.TestCase):  # ← Click to run
    def test_add(self):
        self.assertEqual(2 + 2, 4)

Command:

python3 -m unittest tests.test_example.TestCalculator

def test_subtract(self):  # ← Click to run
    self.assertEqual(5 - 3, 2)

Command:

python3 -m unittest tests.test_example.TestCalculator.test_subtract

Module Execution

Run Python files as modules:

# mypackage/cli.py
if __name__ == "__main__":
    main()

Task: Run module ‘mypackage.cli’

python3 -m mypackage.cli

Glass automatically converts file paths to module names:

src/mypackage/cli.py → src.mypackage.cli
mypackage/cli.py → mypackage.cli

Task Variables

Variable	Description	Example
`PYTHON_ACTIVE_ZED_TOOLCHAIN`	Active Python interpreter	`/path/to/.venv/bin/python3`
`PYTHON_TEST_TARGET`	Test target (pytest or unittest format)	`test_file.py::TestClass::test_method`
`PYTHON_MODULE_NAME`	Module name from file path	`mypackage.cli`

Available Tasks

Execution
Testing

Execute selection: Run selected code
Run file: Execute entire Python file
Run module: Run file as module with -m

Configuration

Language Server Configuration

Pyright/Basedpyright
Virtual Environment

{
  "lsp": {
    "pyright": {
      "settings": {
        "python": {
          "analysis": {
            "typeCheckingMode": "strict",
            "autoImportCompletions": true,
            "diagnosticMode": "workspace"
          }
        }
      }
    }
  }
}

Type checking modes:

off: No type checking
basic: Basic type checking (default)
strict: Strict type checking

Glass automatically configures the virtual environment:

// Sent to language server automatically
{
  "venvPath": ".",
  "venv": ".venv",
  "python": {
    "pythonPath": "/path/to/.venv/bin/python3"
  }
}

You can override manually:

{
  "lsp": {
    "pyright": {
      "settings": {
        "python": {
          "pythonPath": "/custom/path/to/python"
        }
      }
    }
  }
}

Workspace Detection

Glass detects Python projects by finding pyproject.toml:

[tool.poetry]
name = "myproject"
version = "0.1.0"

[tool.poetry.dependencies]
python = "^3.11"

This helps Glass:

Find the project root
Detect package structure
Configure relative imports

Conda/Mamba Support

For Conda environments:

Activation
Environment Selection

Configure Conda manager preference:

{
  "terminal": {
    "detect_venv": {
      "on": {
        "conda_manager": "auto"  // or "conda", "mamba", "micromamba"
      }
    }
  }
}

Glass will activate Conda environments in integrated terminals.

Conda environments from:

CONDA_PREFIX environment variable
Conda installation directory
Miniconda/Anaconda directories

Environments appear in the toolchain picker with their names and Python versions.

Troubleshooting

If the language server can’t find imports, ensure your virtual environment includes all dependencies:

# Recreate environment
rm -rf .venv
python3 -m venv .venv
source .venv/bin/activate  # or .venv\Scripts\activate on Windows
pip install -r requirements.txt

Then restart Glass or run “Python: Restart Language Server”.

Wrong Python Version
Import Errors
Tests Not Found

Check detected Python:

Cmd/Ctrl+Shift+P → “Python: Show Detected Environments”
Verify the correct environment is selected
If not, use “Python: Select Interpreter”

Or check manually:

which python3
python3 --version

For custom import paths, add to pyproject.toml or create a .pth file:

[tool.pyright]
extraPaths = ["src", "lib"]

Or configure in Glass:

{
  "lsp": {
    "pyright": {
      "settings": {
        "python": {
          "analysis": {
            "extraPaths": ["src", "lib"]
          }
        }
      }
    }
  }
}

Ensure test files follow naming conventions:

pytest: test_*.py or *_test.py
unittest: test_*.py in a package with __init__.py

Check test discovery:

# pytest
pytest --collect-only

# unittest
python -m unittest discover

Get Started

Core Features

AI Capabilities

Development

Customization

Language Support

Python Language Support

LSP Servers

Virtual Environment Detection

Detection Methods

Environment Priority

Features

Intelligent Completions

Custom Completion Sorting

Test Framework Integration

Test Runner Selection

pytest (Default)

unittest (Standard Library)

Module Execution

Task Variables

Available Tasks

Configuration

Language Server Configuration

Workspace Detection

Conda/Mamba Support

Troubleshooting

Next Steps

Build docs developers (and LLMs) love

Get Started

Core Features

AI Capabilities

Development

Customization

Language Support

​LSP Servers

​Virtual Environment Detection

​Detection Methods

​Environment Priority

​Features

​Intelligent Completions

​Custom Completion Sorting

​Test Framework Integration

​Test Runner Selection

​pytest (Default)

​unittest (Standard Library)

​Module Execution

​Task Variables

​Available Tasks

​Configuration

​Language Server Configuration

​Workspace Detection

​Conda/Mamba Support

​Troubleshooting

​Next Steps

Build docs developers (and LLMs) love

LSP Servers

Virtual Environment Detection

Detection Methods

Environment Priority

Features

Intelligent Completions

Custom Completion Sorting

Test Framework Integration

Test Runner Selection

pytest (Default)

unittest (Standard Library)

Module Execution

Task Variables

Available Tasks

Configuration

Language Server Configuration

Workspace Detection

Conda/Mamba Support

Troubleshooting

Next Steps