Function computeRequiresPython

packages/python-analysis/src/manifest/package.ts:316–375

* Compute the `requires-python` constraints for a package.

(
  manifest: PythonManifest | undefined,
  workspaceManifest: PythonManifest | undefined,
  configs: PythonConfigs[]
)

 * Compute the `requires-python` constraints for a package.
 */
function computeRequiresPython(
  manifest: PythonManifest | undefined,
  workspaceManifest: PythonManifest | undefined,
  configs: PythonConfigs[]
): PythonConstraint[] {
  const constraints: PythonConstraint[] = [];

  // Check for `.python-version` between manifest and workspace.
  // When present, it takes priority over `requires-python`.
  let hasPythonVersionFile = false;
  for (const configSet of configs) {
    const pythonVersionConfig = configSet[PythonConfigKind.PythonVersion];
    if (pythonVersionConfig !== undefined) {
      constraints.push({
        request: pythonVersionConfig.data,
        source: pythonVersionConfig.path,
        prettySource: pythonVersionConfig.path,
        specifier: pythonVersionConfig.specifier,
      });
      hasPythonVersionFile = true;
      break;
    }
  }

  // Check `requires-python` from nearest package pyproject.toml,
  // but only if no `.python-version` file was found (it takes priority).
  if (!hasPythonVersionFile) {
    const manifestRequiresPython = manifest?.data.project?.['requires-python'];
    if (manifestRequiresPython) {
      const parsed = parsePep440Constraint(manifestRequiresPython);
      if (parsed?.length) {
        const request = pythonRequestFromConstraint(parsed);
        constraints.push({
          request: [request],
          source: manifest.path,
          prettySource: `"requires-python" key in ${manifest.path}`,
          specifier: manifestRequiresPython,
        });
      }
    } else {
      // Check `requires-python` from workspace pyproject.toml
      const workspaceRequiresPython =
        workspaceManifest?.data.project?.['requires-python'];
      if (workspaceRequiresPython) {
        const parsed = parsePep440Constraint(workspaceRequiresPython);
        if (parsed?.length) {
          const request = pythonRequestFromConstraint(parsed);
          constraints.push({
            request: [request],
            source: workspaceManifest.path,
            prettySource: `"requires-python" key in ${workspaceManifest.path}`,
            specifier: workspaceRequiresPython,
          });
        }
      }
    }
  }