[pulsar] branch master updated: [Python] Fixed import when AvroSchema is not being used (#11034)

[si...@apache.org]

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The following commit(s) were added to refs/heads/master by this push:
     new b4fa411  [Python] Fixed import when AvroSchema is not being used (#11034)
b4fa411 is described below

commit b4fa411e775b1cb7c21395fab83a16e60938d147
Author: Matteo Merli <mm...@apache.org>
AuthorDate: Thu Jun 24 04:53:55 2021 +0200

    [Python] Fixed import when AvroSchema is not being used (#11034)
    
    ### Motivation
    
    Fixes #10929
    
    Since by default we're not marking `fastavro` as a dependency, we shouldn't failing when the dependency
    is not there, unless a user is really trying to use `AvroSchema`,  in which case we should give a useful error message.
---
 pulsar-client-cpp/python/pulsar/schema/__init__.py |  3 +-
 pulsar-client-cpp/python/pulsar/schema/schema.py   | 27 ---------
 .../python/pulsar/schema/schema_avro.py            | 67 ++++++++++++++++++++++
 3 files changed, 69 insertions(+), 28 deletions(-)

diff --git a/pulsar-client-cpp/python/pulsar/schema/__init__.py b/pulsar-client-cpp/python/pulsar/schema/__init__.py
index a38513f..150629d 100644
--- a/pulsar-client-cpp/python/pulsar/schema/__init__.py
+++ b/pulsar-client-cpp/python/pulsar/schema/__init__.py
@@ -20,4 +20,5 @@
 from .definition import Record, Field, Null, Boolean, Integer, Long, \
             Float, Double, Bytes, String, Array, Map
 
-from .schema import Schema, BytesSchema, StringSchema, JsonSchema, AvroSchema
+from .schema import Schema, BytesSchema, StringSchema, JsonSchema
+from .schema_avro import AvroSchema
diff --git a/pulsar-client-cpp/python/pulsar/schema/schema.py b/pulsar-client-cpp/python/pulsar/schema/schema.py
index d0da91a..083efc3 100644
--- a/pulsar-client-cpp/python/pulsar/schema/schema.py
+++ b/pulsar-client-cpp/python/pulsar/schema/schema.py
@@ -20,9 +20,7 @@
 
 from abc import abstractmethod
 import json
-import fastavro
 import _pulsar
-import io
 import enum
 
 
@@ -95,28 +93,3 @@ class JsonSchema(Schema):
 
     def decode(self, data):
         return self._record_cls(**json.loads(data))
-
-
-class AvroSchema(Schema):
-    def __init__(self, record_cls):
-        super(AvroSchema, self).__init__(record_cls, _pulsar.SchemaType.AVRO,
-                                         record_cls.schema(), 'AVRO')
-        self._schema = record_cls.schema()
-
-    def _get_serialized_value(self, x):
-        if isinstance(x, enum.Enum):
-            return x.name
-        else:
-            return x
-
-    def encode(self, obj):
-        self._validate_object_type(obj)
-        buffer = io.BytesIO()
-        m = {k: self._get_serialized_value(v) for k, v in obj.__dict__.items()}
-        fastavro.schemaless_writer(buffer, self._schema, m)
-        return buffer.getvalue()
-
-    def decode(self, data):
-        buffer = io.BytesIO(data)
-        d = fastavro.schemaless_reader(buffer, self._schema)
-        return self._record_cls(**d)
diff --git a/pulsar-client-cpp/python/pulsar/schema/schema_avro.py b/pulsar-client-cpp/python/pulsar/schema/schema_avro.py
new file mode 100644
index 0000000..2afa9db
--- /dev/null
+++ b/pulsar-client-cpp/python/pulsar/schema/schema_avro.py
@@ -0,0 +1,67 @@
+#
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+#
+
+import _pulsar
+import io
+import enum
+
+from .schema import Schema
+
+try:
+    import fastavro
+    HAS_AVRO = True
+except ModuleNotFoundError:
+    HAS_AVRO = False
+
+if HAS_AVRO:
+    class AvroSchema(Schema):
+        def __init__(self, record_cls):
+            super(AvroSchema, self).__init__(record_cls, _pulsar.SchemaType.AVRO,
+                                             record_cls.schema(), 'AVRO')
+            self._schema = record_cls.schema()
+
+        def _get_serialized_value(self, x):
+            if isinstance(x, enum.Enum):
+                return x.name
+            else:
+                return x
+
+        def encode(self, obj):
+            self._validate_object_type(obj)
+            buffer = io.BytesIO()
+            m = {k: self._get_serialized_value(v) for k, v in obj.__dict__.items()}
+            fastavro.schemaless_writer(buffer, self._schema, m)
+            return buffer.getvalue()
+
+        def decode(self, data):
+            buffer = io.BytesIO(data)
+            d = fastavro.schemaless_reader(buffer, self._schema)
+            return self._record_cls(**d)
+
+else:
+    class AvroSchema(Schema):
+        def __init__(self, _record_cls):
+            raise Exception("Avro library support was not found. Make sure to install Pulsar client " +
+                            "with Avro support: pip3 install 'pulsar-client[avro]'")
+
+        def encode(self, obj):
+            pass
+
+        def decode(self, data):
+            pass