Glue DynamicFrame show method yields nothing

Question

I'm using a Notebook together with a Glue Dev Endpoint to load data from S3 into a Glue DynamicFrame. The `printSchema` method works fine but the `show` method yields nothing although the dataframe is not empty. Converting the DynamicFrame into a Spark DataFrame actually yields a result (`df.toDF().show()`). Here the dummy code that I'm using

```python
glueContext = GlueContext(spark.sparkContext)

df = glueContext.create_dynamic_frame_from_options(
    connection_type="s3", 
    connection_options = {
        "paths": [f"s3://bucketname/filename"]},
    format="json",
    format_options={"multiline": True}
)

df.printSchema()
df.show()
```
This problem was posted on Stackoverflow before: https://stackoverflow.com/questions/56013334/spark-dynamic-frame-show-method-yields-nothing

Why does the `show` method yield nothing? Is this a bug or is there something that I'm missing to make this work?

Answer

Hello,

I would like to inform DynamicFrame is similar to a DataFrame, except that each record is self-describing, so no schema is required initially. Instead, AWS Glue computes a schema on-the-fly when required. Basically Glue DynamicFrame is based on RDD due to which show() method does not work directly and you need to convert dynamic frame to dataframe first to check the data in tabular format.

```
dyf.printSchema()
dyf.toDF().show()

```

Glue DynamicFrame show method yields nothing

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