Function detectPythonEntrypoint

packages/python/src/entrypoint.ts:492–595

(
  framework: PythonFramework | undefined,
  workPath: string,
  configuredEntrypoint?: { filePath: string; varName?: string },
  service?: { type?: ServiceType; trigger?: JobTrigger }
)

 * Detect a Python entrypoint path for a given framework relative to workPath, or return null if not found.
 */
export async function detectPythonEntrypoint(
  framework: PythonFramework | undefined,
  workPath: string,
  configuredEntrypoint?: { filePath: string; varName?: string },
  service?: { type?: ServiceType; trigger?: JobTrigger }
): Promise<DetectedPythonEntrypoint | null> {
  // If a configured entrypoint was provided, check it first
  if (configuredEntrypoint) {
    const { filePath: configEntryFile, varName: configEntryVar } =
      configuredEntrypoint;
    const entrypoint = configEntryFile.endsWith('.py')
      ? configEntryFile
      : `${configEntryFile}.py`;
    const entrypointExists = await fileExists(join(workPath, entrypoint));

    if (!entrypointExists) {
      return {
        error: new NowBuildError({
          code: 'PYTHON_ENTRYPOINT_NOT_FOUND',
          message: `Configured Python entrypoint "${entrypoint}" was not found.`,
          link: PYTHON_ENTRYPOINT_DOCS_URL,
          action: 'Learn More',
        }),
      };
    }

    let varName: string | null =
      configEntryVar ?? (await checkEntrypoint(workPath, entrypoint));

    if (!varName) {
      // Queue-backed and schedule-triggered services create an `app` dynamically.
      // Any other service type (including workflow-triggered jobs) uses the
      // normal WSGI/ASGI entrypoint detection.
      const needsDynamicApp =
        !!service &&
        (isScheduleTriggeredService(service) ||
          isQueueTriggeredService(service) ||
          isWorkflowTriggeredService(service));
      if (needsDynamicApp) {
        varName = 'app';
      }
    }

    if (varName) {
      debug(`Using configured Python entrypoint: ${entrypoint}`);
      return { entrypoint: { entrypoint, variableName: varName } };
    } else {
      return {
        error: new NowBuildError({
          code: 'PYTHON_ENTRYPOINT_NOT_FOUND',
          message: `Could not find a top-level "app", "application", or "handler" in "${entrypoint}".`,
          link: PYTHON_ENTRYPOINT_DOCS_URL,
          action: 'Learn More',
        }),
      };
    }
  }
  if (!framework) {