def check_controller_existence(base_package, directory, name):
    filename = os.path.join(base_package, 'controllers', directory,
                            name + '.py')
    if os.path.exists(filename):
        raise BadCommand('Controller %s already exists.' %
                         os.path.join(directory, name))
alias for clize.help.DispatcherHelper, avoiding circular import
dataset/ETHPy150Open Pylons/pylons/pylons/commands.py/check_controller_existence--crossover with--dataset/ETHPy150Open epsy/clize/clize/runner.py/_dispatcher_helper