gaoran10 commented on a change in pull request #12914:
URL: https://github.com/apache/pulsar/pull/12914#discussion_r754105818
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File path: site2/docs/client-libraries-python.md
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@@ -327,6 +272,198 @@ The schema definition is like this.
}
```
+### Declare and validate schema
+
+You can send messages using `BytesSchema`, `StringSchema`, `AvroSchema`, and
`JsonSchema`.
+
+<!--DOCUSAURUS_CODE_TABS-->
+
+<!--BytesSchema-->
+
+You can send byte data using a `BytesSchema`.
+
+**Example**
+
+```python
+producer = client.create_producer(
+ 'bytes-schema-topic',
+ schema=BytesSchema())
+producer.send(b"Hello")
+
+consumer = client.subscribe(
+ 'bytes-schema-topic',
+ 'sub',
+ schema=BytesSchema())
+msg = consumer.receive()
+data = msg.value()
+```
+
+<!--StringSchema-->
+
+You can send string data using a `StringSchema`.
+
+**Example**
+
+```python
+producer = client.create_producer(
+ 'string-schema-topic',
+ schema=StringSchema())
+producer.send("Hello")
+
+consumer = client.subscribe(
+ 'string-schema-topic',
+ 'sub',
+ schema=StringSchema())
+msg = consumer.receive()
+str = msg.value()
+```
+
+<!--AvroSchema-->
+
+You can declare an `AvroSchema` using one of the following methods.
+
+#### Method 1: Record
+
+You can declare an `AvroSchema` by passing a class that inherits
+from `pulsar.schema.Record` and defines the fields as
+class variables.
+
+**Example**
+
+```python
+class Example(Record):
+ a = Integer()
+ b = Integer()
+
+producer = client.create_producer(
+ 'avro-schema-topic',
+ schema=AvroSchema(Example))
+r = Example(a=1, b=2)
+producer.send(r)
+
+consumer = client.subscribe(
+ 'avro-schema-topic',
+ 'sub',
+ schema=AvroSchema(Example))
+msg = consumer.receive()
+e = msg.value()
+```
+
+After the producer is created, the Pulsar broker validates that the existing
topic schema is "Avro" type and that the format is compatible with the schema
definition of the `Example` class. If the format of the topic schema is
incompatible with the schema definition, an exception occurs in the producer
creation.
Review comment:
Before creating a producer, the Pulsar broker will check the schema
compatible first, if there is a schema compatible problem, an exception occurs
in the producer creation.
By the way, the schema compatible check applies to all schema types, maybe
we don't need to mention it in AvroSchema.
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