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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def help(project, task, step, variables):
 """Run a help step."""


    task_name = step.args or variables['task']

    try:
        task = project.find_task(task_name)
    except NoSuchTaskError as e:
        yield events.task_not_found(task_name, e.similarities)
        raise StopTask

    text = f'# {task.name}\n'
    text += '\n'
    text += task.description
    text += '\n\n'
    text += 'Variables: {}'.format(', '.join(task.variables))

    yield events.help_output(text)