[jira] [Commented] (AVRO-3118) Namespace with empty string is not treated as null in Python API

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[jira] [Commented] (AVRO-3118) Namespace with empty string is not treated as null in Python API

Dave Cole (Jira)

    [ https://issues.apache.org/jira/browse/AVRO-3118?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17347254#comment-17347254 ]

Michael A. Smith commented on AVRO-3118:
----------------------------------------

My Java is not strong, but I was able to read the schema in without error using the java tools:

{code:sh}
$ cd lang/java
$ pbpaste | jq -c | tee schema.json  # pbpaste is macos-specific paste from clipboard
{"type":"record","name":"my_schema","namespace":"my_ns","fields":[{"name":"field_a","type":{"type":"record","name":"row","namespace":"","fields":[{"name":"subfield","type":"string"}]}},{"name":"field_b","type":"row"}]}
$ ./build.sh dist

$ java -jar tools/target/avro-tools-1.11.0-SNAPSHOT.jar random --count 1 --schema-file schema.json - | java -jar tools/target/avro-tools-1.11.0-SNAPSHOT.jar tojson - | jq -r .
{
  "field_a": {
    "subfield": "uvqklmwumlywpfjfnijmahjhsbdlcvucfd"
  },
  "field_b": {
    "subfield": "jlhyhqrbwjfojdapwripscvsglvuvkjmkxumag"
  }
}
{code}

So Java accepts this schema, at least.

> Namespace with empty string is not treated as null in Python API
> ----------------------------------------------------------------
>
>                 Key: AVRO-3118
>                 URL: https://issues.apache.org/jira/browse/AVRO-3118
>             Project: Apache Avro
>          Issue Type: Bug
>          Components: python
>    Affects Versions: 1.10.2
>            Reporter: Frank Mieves
>            Assignee: Michael A. Smith
>            Priority: Blocker
>
> Hi,
> based on [the AVRO documentation|https://avro.apache.org/docs/current/spec.html#names] an empty string may also be used as a namespace to indicate the null namespace.
> The Python package doesn't do that. Following example will fail when parsing:
> {code:python}
> import avro.schema
> schema_str="""
> {"type": "record", "name": "my_schema", "namespace": "my_ns",
>  "fields": [{"name": "field_a", "type": {"type": "record", "name": "row", "namespace": "",
>  "fields": [{"name": "subfield", "type": "string"}]}},
>  {"name": "field_b", "type": "row"}
>  ]}
> """
> schema = avro.schema.parse(schema_str)
> {code}
> Raised exception is "SchemaParseException: Type property "row" not a valid Avro schema: Could not make an Avro Schema object from row."
> If I set the namespace in the in the subfield to null it's working.
> Problem for me is, that I can't change the schema definition. The schema is in the Kafka schema repository. The Kafka AVRO consumer receives this from the schema registry server with an empty string.
> I could fix this by adding a check in the parser source schema.py:
>  
> {code:python}
> ...
> return writer.type == self.type and (self.type == 'request' or self.check_props(writer, ['fullname']))
> def __init__(self, name, namespace, fields, names=None, schema_type='record', doc=None, other_props=None):
>     # Fixing empty namespace
>     if namespace == '':
>         namespace = None
>  
>     # Ensure valid ctor args
>     if fields is None:
>         ...
> {code}
>  
>  



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