pyproject.toml (Python) to JSON Conversion

pyproject.toml is the standard configuration file for modern Python projects, defined in PEP 518 and PEP 621. It consolidates build system configuration, project metadata, and tool settings into a single TOML file.

A typical pyproject.toml:

[build-system]
requires = ["hatchling"]
build-backend = "hatchling.build"

[project]
name = "my-package"
version = "1.0.0"
description = "A sample Python package"
readme = "README.md"
requires-python = ">=3.9"
license = {text = "MIT"}
authors = [
  {name = "Alice", email = "alice@example.com"},
]
dependencies = [
  "requests>=2.28",
  "pydantic>=2.0",
]

[project.optional-dependencies]
dev = ["pytest>=7.0", "ruff>=0.1"]

[tool.ruff]
line-length = 88
target-version = "py39"

[tool.ruff.lint]
select = ["E", "F", "I"]

[tool.pytest.ini_options]
testpaths = ["tests"]
addopts = "-v --tb=short"

Converts to JSON:

{
  "build-system": {
    "requires": ["hatchling"],
    "build-backend": "hatchling.build"
  },
  "project": {
    "name": "my-package",
    "version": "1.0.0",
    "description": "A sample Python package",
    "readme": "README.md",
    "requires-python": ">=3.9",
    "license": {"text": "MIT"},
    "authors": [
      {"name": "Alice", "email": "alice@example.com"}
    ],
    "dependencies": [
      "requests>=2.28",
      "pydantic>=2.0"
    ]
  },
  "project.optional-dependencies": {
    "dev": ["pytest>=7.0", "ruff>=0.1"]
  },
  "tool": {
    "ruff": {
      "line-length": 88,
      "target-version": "py39",
      "lint": {
        "select": ["E", "F", "I"]
      }
    },
    "pytest": {
      "ini_options": {
        "testpaths": ["tests"],
        "addopts": "-v --tb=short"
      }
    }
  }
}

Notable conversion details:

• [tool.*] sections create deeply nested JSON under the tool key. Each tool (ruff, pytest, mypy) gets its own namespace.
• Authors use the array of tables pattern with inline tables.
• Optional dependencies map group names to arrays of PEP 508 requirement strings.
• Dotted table headers like [tool.ruff.lint] produce nested JSON objects: tool -> ruff -> lint.

The JSON representation is useful for programmatic analysis of Python project configurations, dependency resolution tools, and CI/CD systems that need to extract metadata.