“模拟”对象没有属性“__getitem__”

Question

按照Mocking a Dictionary with MagicMock 的示例后，我有以下模拟设置：

mock_writer = Mock()
mock_reader = Mock()
mock_format = Mock()
mock_option = Mock()
mock_load = MagicMock()

test_dict = {"Bus_No": Mock(), "Team_No": Mock()}

def getitem(name):
    return test_dict[name]

mock_load.__getitem__.side_effect = getitem

mock_option.load.return_value = mock_load
mock_format.option.return_value = mock_option
mock_reader.format.return_value = mock_format
mock_reader.write.return_value = mock_writer
mock_spark = Mock()
mock_spark.read.return_value = mock_reader

Driver(mock_spark).run()

这里是驱动类：

def __init__(self, spark):
    self.spark = spark

def run(self):

    partition_names = ["Bus_No", "Team_No"]

    df = self.spark.read\
        .format("com.databricks.spark.avro")\
        .option("avroSchema", schema)\
        .load("{0}{1}*.avro".format(job.SourcePath, os.path.sep))

    partition_columns = [df[x] for x in partition_names]

然后它返回这个错误：

partition_columns = [df[x] for x in partition_names]
TypeError: 'Mock' object has no attribute '__getitem__'

Answer 1

事实证明，因为read 不是我不应该使用来自mock_spark.read 的return_value 的方法。变化如下：

mock_spark.read = mock_reader