def ensure_dependencies():
    if not shell('python', '--version', capture=True).startswith('Python 2.7'):
        raise EnvironmentError('Python 2.7 is required.')

    try:
        shell('pg_config' + ext, capture=True)
    except __HOLE__ as e:
        if e.errno != os.errno.ENOENT:
            raise
        raise EnvironmentError('Postgresql is required. (Make sure pg_config is on your PATH.)')
dataset/ETHPy150Open gratipay/gratipay.com/gratipay.py/ensure_dependencies