Changing datatype of a specific column of dynamicframe in aws glue

Question

Greetings all experts,

I've faced a problem and I need a solution. Please help me with this.

So, I have a dynamic frame created from an XML file stored in s3.

The frame has a nested field ' ReceiptNumber ' and the dynamic frame's schema is like below:

root
|-- Receipt: struct
|    |-- Front: struct
|    |    |-- FrontNumber: string
|    |    |-- CountryorTerritoryCode: string
|    |    |-- TaxId: string
|    |-- ReceiptAmount: double
|    |-- ReceiptCurrencyCode: string
|    |-- ReceiptDateCCYYMMDD: int
|    |-- ReceiptNumber: double
|    |-- TaxVarianceAmount: double
|    |-- TransferDetails: array
|    |    |-- element: struct
|    |    |    |-- BillCategoryCode: string
|    |    |    |-- BillCategoryDetailCode: string
|    |    |    |-- Porting: array
|    |    |    |    |-- element: struct
|    |    |    |    |    |-- AddressDetails: struct
|    |    |    |    |    |    |-- ConsigneeAddress: struct
|    |    |    |    |    |    |    |-- Address: struct
|    |    |    |    |    |    |    |    |-- AddressText2: string
|    |    |    |    |    |    |    |    |-- CityName: string
|    |    |    |    |    |    |    |    |-- CountryorTerritoryCode: string
|    |    |    |    |    |    |    |    |-- PostalCode: string
|    |    |    |    |    |    |    |    |-- StateCode: string
|    |    |    |    |    |    |    |    |-- StreetAddress: string
|    |    |    |    |    |    |    |-- Addressee: struct
|    |    |    |    |    |    |    |    |-- Name: string
|    |    |    |    |    |    |    |-- Attention: struct
|    |    |    |    |    |    |    |    |-- Name: string
|    |    |    |    |    |    |-- SenderAddress: struct
|    |    |    |    |    |    |    |-- Address: struct
|    |    |    |    |    |    |    |    |-- CityName: string
|    |    |    |    |    |    |    |    |-- CountryorTerritoryCode: string
|    |    |    |    |    |    |    |    |-- PostalCode: string
|    |    |    |    |    |    |    |    |-- StateCode: string
|    |    |    |    |    |    |    |    |-- StreetAddress: string
|    |    |    |    |    |    |    |-- Addressee: struct
|    |    |    |    |    |    |    |    |-- Name: string
|    |    |    |    |    |    |    |-- Attention: struct
|    |    |    |    |    |    |    |    |-- Name: string
|    |    |    |    |    |    |-- ThirdPartyAddress: struct
|    |    |    |    |    |    |    |-- Address: struct
|    |    |    |    |    |    |    |    |-- CityName: string
|    |    |    |    |    |    |    |    |-- CountryorTerritoryCode: string
|    |    |    |    |    |    |    |    |-- PostalCode: string
|    |    |    |    |    |    |    |    |-- StreetAddress: string
|    |    |    |    |    |    |    |-- Addressee: struct
|    |    |    |    |    |    |    |    |-- Name: string
|    |    |    |    |    |    |    |-- Attention: struct
|    |    |    |    |    |    |    |    |-- Name: string
|    |    |    |    |    |-- BillOptionCode: string
|    |    |    |    |    |-- LeadPortingNumber: string
|    |    |    |    |    |-- Package: array
|    |    |    |    |    |    |-- element: struct
|    |    |    |    |    |    |    |-- BillDetails: struct
|    |    |    |    |    |    |    |    |-- Bill: array
|    |    |    |    |    |    |    |    |    |-- element: struct
|    |    |    |    |    |    |    |    |    |    |-- BillInformation: array
|    |    |    |    |    |    |    |    |    |    |    |-- element: struct
|    |    |    |    |    |    |    |    |    |    |    |    |-- BasisCurrencyCode: string
|    |    |    |    |    |    |    |    |    |    |    |    |-- BasisValue: double
|    |    |    |    |    |    |    |    |    |    |    |    |-- BilldUnitQuantity: int
|    |    |    |    |    |    |    |    |    |    |    |    |-- CurrencyCode: string
|    |    |    |    |    |    |    |    |    |    |    |    |-- DescriptionCode: string
|    |    |    |    |    |    |    |    |    |    |    |    |-- DescriptionOfBills: string
|    |    |    |    |    |    |    |    |    |    |    |    |-- ExemptionAmount: double
|    |    |    |    |    |    |    |    |    |    |    |    |-- IncentiveAmount: double
|    |    |    |    |    |    |    |    |    |    |    |    |-- NetAmount: double
|    |    |    |    |    |    |    |    |    |    |    |    |-- TaxIndicator: double
|    |    |    |    |    |    |    |    |    |    |-- ClassificationCode: string
|    |    |    |    |    |    |    |-- ContainerType: string
|    |    |    |    |    |    |    |-- MiscellaneousDetails: struct
|    |    |    |    |    |    |    |    |-- MiscellaneousLineItems: struct
|    |    |    |    |    |    |    |    |    |-- LineItem: struct
|    |    |    |    |    |    |    |    |    |    |-- LineNumber: int
|    |    |    |    |    |    |    |    |    |    |-- LineText: string
|    |    |    |    |    |    |    |-- PackageBillableKeyedDimensions: struct
|    |    |    |    |    |    |    |    |-- Height: double
|    |    |    |    |    |    |    |    |-- Length: double
|    |    |    |    |    |    |    |    |-- Width: double
|    |    |    |    |    |    |    |-- PackageDimension: struct
|    |    |    |    |    |    |    |    |-- Height: double
|    |    |    |    |    |    |    |    |-- Length: double
|    |    |    |    |    |    |    |    |-- UnitOfMeasure: string
|    |    |    |    |    |    |    |    |-- Width: double
|    |    |    |    |    |    |    |-- PackageKeyedDimensions: struct
|    |    |    |    |    |    |    |    |-- Height: double
|    |    |    |    |    |    |    |    |-- Length: double
|    |    |    |    |    |    |    |    |-- UnitOfMeasure: string
|    |    |    |    |    |    |    |    |-- Width: double
|    |    |    |    |    |    |    |-- PackageQuantity: struct
|    |    |    |    |    |    |    |    |-- ActualQuantity: struct
|    |    |    |    |    |    |    |    |    |-- Quantity: int
|    |    |    |    |    |    |    |-- PackageWeight: struct
|    |    |    |    |    |    |    |    |-- ActualWeight: struct
|    |    |    |    |    |    |    |    |    |-- UnitOfMeasure: string
|    |    |    |    |    |    |    |    |    |-- Weight: double
|    |    |    |    |    |    |    |    |-- BilledWeight: struct
|    |    |    |    |    |    |    |    |    |-- UnitOfMeasure: string
|    |    |    |    |    |    |    |    |    |-- Weight: double
|    |    |    |    |    |    |    |    |-- BilledWeightType: double
|    |    |    |    |    |    |    |-- TrackingNumber: string
|    |    |    |    |    |    |    |-- Zone: int
|    |    |    |    |    |-- PayerRoleCd: int
|    |    |    |    |    |-- PickUpRecordNumber: long
|    |    |    |    |    |-- PortingReferences: struct
|    |    |    |    |    |    |-- Reference: array
|    |    |    |    |    |    |    |-- element: struct
|    |    |    |    |    |    |    |    |-- ReferenceNumber: string
|    |    |    |    |    |    |    |    |-- Sequence: int
|    |    |    |    |    |-- TransferDateCCYYMMDD: int
|    |-- TypeCode: string
|    |-- TypeDetailCode: double

What I want to change before writing the dynamic frame is to make the field ' ReceiptNumber ' a string type like below

....
....
|    |-- ReceiptCurrencyCode: string
|    |-- ReceiptDateCCYYMMDD: int
|    |-- 
|    |-- TaxVarianceAmount: double
....
....

Can it be possible via apply_mapping ?

Is there any alternative solution?

Answer 1

At last, I was able to solve it with a little bit of a different approach.

So, to recap, I have a Glue ETL type job, written in python script.

It was responsible for processing an XML file. After processing the XML file, its schema was like the above, as I mentioned in the question.

So, I wanted to change the type of one of its nodes which is 'ReceiptNumber' to string from int .

So, first I created a dynamic frame from the s3 file as usual

d0  = glueContext.create_dynamic_frame.from_options( connection_type = "s3", connection_options={"paths": [s3_path]}, format = "xml", format_options={"rowTag": "ReceiptDetails"}, transformation_ctx = "d0")

Then, turned the dynamic frame into pyspark dataframe like below

df = d0.toDF();

Then, I utilized the function written in the following link that how we can modify a nested struct field and its type.

Pyspark: How to Modify a Nested Struct Field

From the function, I created a new_schema that utilized like below and converted it into a new dynamicframe like below.

df = df.withColumn("Receipt_json", to_json("Receipt")).drop("Receipt")
df = df.withColumn("Receipt", from_json("Receipt_json", new_schema)).drop("Receipt_json")
d0 = DynamicFrame.fromDF(df, glueContext, "d0")

From the new dynamicframe which has a modified field 'ReceiptNumber' (from int to string ), I created a JSON schema like below.

receiptSchema = d0.schema()
withReceiptSchema = json.dumps(receiptSchema.jsonValue())

At last, I created the schema again like below with new schema and wrote it down in a JSON file like below.

d0  = glueContext.create_dynamic_frame.from_options( connection_type = "s3", connection_options={"paths": [s3_path]}, format = "xml", format_options={"withSchema": withReceiptSchema, "rowTag": "ReceiptDetails"}, transformation_ctx = "d0")

# writing the down the data from above schema in a JSON file
glueContext.write_dynamic_frame.from_options(frame = d0, connection_type = "s3", connection_options = {"path": s3_write_path}, format = "json")

I hope, if someone falls into this sort of error or roadblock while working on Aws Glue Jobs, this answer could be of help.

Answer 2

I had a similar problem where I had to add / delete and change the types of many columns. For my case I ended up using the Map transformation that applies a function to all records of a DynamicFrame .

inputDyf = glueContext.create_dynamic_frame_from_options(
    ...
)


def mapping(record: Dict[str, Any]):
    record["UpdatedAt"] = int(time.mktime(datetime.date.today().timetuple()))
    record["SomeVal"] = int(record["SomeVal"])

    # ... put, del and other dict operations
    return record 

mapped_dyF = Map.apply(frame=inputDyf, f=mapping)

Also you can specify the schema on the create_dynamic_frame_from_options method when using the XML format :

schema = StructType([ 
  Field("name", StringType()),
])

datasource0 = create_dynamic_frame_from_options(
    connection_type, 
    connection_options={"paths": ["s3://xml_bucket/someprefix"]},
    format="xml", 
    format_options={"withSchema": json.dumps(schema.jsonValue())},
    transformation_ctx = ""
)

# or directly as an string
datasource0 = create_dynamic_frame_from_options(
    connection_type, 
    connection_options={"paths": ["s3://xml_bucket/someprefix"]},
    format="xml", 
    format_options={
        "withSchema": """
{
  "dataType": "struct",
  "properties": {},
  "fields": [
    {
      "name": "name",
      "container": {
        "dataType": "string",
        "properties": {}
      },
      "properties": {}
    }
  ]
}
    """},
    transformation_ctx = ""
)