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API Reference

Manual reference for the depcon API. Source: src/depcon/.

depcon.models

Data models for dependency conversion. models.py

DependencySpec

Represents a single dependency specification (name, version_specs, extras, url, path, editable, markers).

  • to_string() — pip-compatible format (includes -e flags, local paths).
  • to_pep621_string() — PEP 621 format for pyproject.toml (omits editable flags and local paths).

DependencyGroup

Represents a group of dependencies (e.g. dev, test, docs).

  • include_groups: list[str] — PEP 735 include-group references (e.g., dev group includes test group).
  • add_dependency(), remove_dependency().

ProjectConfig

Complete project configuration (name, version, dependencies, optional_dependencies, dependency_groups, build_system, etc.).

  • license: str | dict | None — PEP 639 SPDX string (preferred) or legacy dict format.
  • requires_python — defaults to ">=3.12".
  • add_dependency(), get_dependency_group(), create_dependency_group().

ConversionOptions

Options for conversion: input files, output path, backup, append, group names, resolve, sort, build_backend, etc.

depcon.parsers

Parsing of requirements file formats. parsers.py

RequirementsParser

Parser for requirements.txt and requirements.in. parse() -> list[DependencySpec].

parse_requirements_file

parse_requirements_file(file_path: Path) -> list[DependencySpec] Parse a requirements file and return dependencies. Chooses RequirementsParser or PipToolsParser by content.

group_dependencies_by_type

group_dependencies_by_type(dependencies: list[DependencySpec]) -> dict[str, list[DependencySpec]] Group dependencies into main, dev, test, docs by package-name heuristics.

depcon.generators

Creation and manipulation of pyproject.toml. generators.py

parse_dep_string

parse_dep_string(dep_str: str) -> DependencySpec | None Parse a PEP 621 dependency string (e.g. "click>=8.0") into a DependencySpec. Returns None on invalid input.

PyProjectGenerator

Generate pyproject.toml from ProjectConfig.

  • generate_toml_content() -> dict — builds the full TOML structure.
  • write_to_file(file_path, backup=True) — writes TOML using tomli_w.
  • PEP 639: license emitted as SPDX string. Old dict formats normalized.
  • PEP 735: include-group entries emitted before regular dependencies.

PyProjectUpdater

Update existing pyproject.toml with new dependencies.

  • load_config() -> ProjectConfig — loads and parses an existing pyproject.toml (public API).
  • update_with_dependencies(main_deps, dev_deps, test_deps, docs_deps, use_dependency_groups).

DependencyMerger

Merge dependencies from multiple sources with optional append mode.

  • merge_dependencies(existing, new) -> list[DependencySpec].
  • merge_dependency_groups(existing, new) -> dict[str, DependencyGroup].

depcon.cli

Command-line interface. cli.py

Command Description
main Click group; depcon --version, depcon --help.
convert Convert requirements files to pyproject.toml.
show Show dependencies from pyproject.toml (table, json, yaml).
validate Validate pyproject.toml dependencies.
list_groups List all dependency groups.
check Check for duplicates and other issues.
export Export dependencies to requirements.txt.
diff Diff pyproject.toml vs requirements files.
sync Sync pyproject.toml to requirements files.

Run depcon --help and depcon <command> --help for options.