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Posted to commits@pulsar.apache.org by GitBox <gi...@apache.org> on 2020/06/05 02:07:12 UTC
[GitHub] [pulsar] Anonymitaet commented on a change in pull request #7148: [Doc]--Add negative acknowledgement to python client docs.
Anonymitaet commented on a change in pull request #7148:
URL: https://github.com/apache/pulsar/pull/7148#discussion_r435650815
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File path: site2/website/versioned_docs/version-2.4.0/client-libraries-python.md
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@@ -0,0 +1,283 @@
+---
+id: version-2.4.0-client-libraries-python
+title: The Pulsar Python client
+sidebar_label: Python
+original_id: client-libraries-python
+---
+
+The Pulsar Python client library is a wrapper over the existing [C++ client library](client-libraries-cpp.md) and exposes all of the [same features](/api/cpp). You can find the code in the [`python` subdirectory](https://github.com/apache/pulsar/tree/master/pulsar-client-cpp/python) of the C++ client code.
+
+## Installation
+
+You can install the [`pulsar-client`](https://pypi.python.org/pypi/pulsar-client) library either via [PyPi](https://pypi.python.org/pypi), using [pip](#installation-using-pip), or by building the library from source.
+
+### Installation using pip
+
+To install the `pulsar-client` library as a pre-built package using the [pip](https://pip.pypa.io/en/stable/) package manager:
+
+```shell
+$ pip install pulsar-client=={{pulsar:version_number}}
+```
+
+Installation via PyPi is available for the following Python versions:
+
+Platform | Supported Python versions
+:--------|:-------------------------
+| MacOS<br /> 10.11 (El Capitan) — 10.12 (Sierra) — 10.13 (High Sierra) — 10.14 (Mojave)<br />| 2.7, 3.7
+|Linux | 2.7, 3.4, 3.5, 3.6, 3.7
+
+### Installing from source
+
+To install the `pulsar-client` library by building from source, follow [these instructions](client-libraries-cpp.md#compilation) and compile the Pulsar C++ client library. That will also build the Python binding for the library.
Review comment:
```suggestion
To install the `pulsar-client` library by building from source, follow [these instructions](client-libraries-cpp.md#compilation) and compile the Pulsar C++ client library. That also builds the Python binding for the library.
```
##########
File path: site2/website/versioned_docs/version-2.4.0/client-libraries-python.md
##########
@@ -0,0 +1,283 @@
+---
+id: version-2.4.0-client-libraries-python
+title: The Pulsar Python client
+sidebar_label: Python
+original_id: client-libraries-python
+---
+
+The Pulsar Python client library is a wrapper over the existing [C++ client library](client-libraries-cpp.md) and exposes all of the [same features](/api/cpp). You can find the code in the [`python` subdirectory](https://github.com/apache/pulsar/tree/master/pulsar-client-cpp/python) of the C++ client code.
+
+## Installation
+
+You can install the [`pulsar-client`](https://pypi.python.org/pypi/pulsar-client) library either via [PyPi](https://pypi.python.org/pypi), using [pip](#installation-using-pip), or by building the library from source.
+
+### Installation using pip
+
+To install the `pulsar-client` library as a pre-built package using the [pip](https://pip.pypa.io/en/stable/) package manager:
+
+```shell
+$ pip install pulsar-client=={{pulsar:version_number}}
+```
+
+Installation via PyPi is available for the following Python versions:
+
+Platform | Supported Python versions
+:--------|:-------------------------
+| MacOS<br /> 10.11 (El Capitan) — 10.12 (Sierra) — 10.13 (High Sierra) — 10.14 (Mojave)<br />| 2.7, 3.7
+|Linux | 2.7, 3.4, 3.5, 3.6, 3.7
+
+### Installing from source
+
+To install the `pulsar-client` library by building from source, follow [these instructions](client-libraries-cpp.md#compilation) and compile the Pulsar C++ client library. That will also build the Python binding for the library.
+
+To install the built Python bindings:
+
+```shell
+$ git clone https://github.com/apache/pulsar
+$ cd pulsar/pulsar-client-cpp/python
+$ sudo python setup.py install
+```
+
+## API Reference
+
+The complete Python API reference is available at [api/python](/api/python).
+
+## Examples
+
+Below you'll find a variety of Python code examples for the `pulsar-client` library.
Review comment:
```suggestion
You can find a variety of Python code examples for the `pulsar-client` library as below.
```
##########
File path: site2/website/versioned_docs/version-2.4.0/client-libraries-python.md
##########
@@ -0,0 +1,283 @@
+---
+id: version-2.4.0-client-libraries-python
+title: The Pulsar Python client
+sidebar_label: Python
+original_id: client-libraries-python
+---
+
+The Pulsar Python client library is a wrapper over the existing [C++ client library](client-libraries-cpp.md) and exposes all of the [same features](/api/cpp). You can find the code in the [`python` subdirectory](https://github.com/apache/pulsar/tree/master/pulsar-client-cpp/python) of the C++ client code.
+
+## Installation
+
+You can install the [`pulsar-client`](https://pypi.python.org/pypi/pulsar-client) library either via [PyPi](https://pypi.python.org/pypi), using [pip](#installation-using-pip), or by building the library from source.
+
+### Installation using pip
+
+To install the `pulsar-client` library as a pre-built package using the [pip](https://pip.pypa.io/en/stable/) package manager:
+
+```shell
+$ pip install pulsar-client=={{pulsar:version_number}}
+```
+
+Installation via PyPi is available for the following Python versions:
+
+Platform | Supported Python versions
+:--------|:-------------------------
+| MacOS<br /> 10.11 (El Capitan) — 10.12 (Sierra) — 10.13 (High Sierra) — 10.14 (Mojave)<br />| 2.7, 3.7
+|Linux | 2.7, 3.4, 3.5, 3.6, 3.7
+
+### Installing from source
+
+To install the `pulsar-client` library by building from source, follow [these instructions](client-libraries-cpp.md#compilation) and compile the Pulsar C++ client library. That will also build the Python binding for the library.
+
+To install the built Python bindings:
+
+```shell
+$ git clone https://github.com/apache/pulsar
+$ cd pulsar/pulsar-client-cpp/python
+$ sudo python setup.py install
+```
+
+## API Reference
+
+The complete Python API reference is available at [api/python](/api/python).
+
+## Examples
+
+Below you'll find a variety of Python code examples for the `pulsar-client` library.
+
+### Producer example
+
+This creates a Python producer for the `my-topic` topic and send 10 messages on that topic:
+
+```python
+import pulsar
+
+client = pulsar.Client('pulsar://localhost:6650')
+
+producer = client.create_producer('my-topic')
+
+for i in range(10):
+ producer.send(('Hello-%d' % i).encode('utf-8'))
+
+client.close()
+```
+
+### Consumer example
+
+This creates a consumer with the `my-subscription` subscription on the `my-topic` topic, listen for incoming messages, print the content and ID of messages that arrive, and acknowledge each message to the Pulsar broker:
+
+```python
+consumer = client.subscribe('my-topic', 'my-subscription')
+
+while True:
+ msg = consumer.receive()
+ try:
+ print("Received message '{}' id='{}'".format(msg.data(), msg.message_id()))
+ # Acknowledge successful processing of the message
+ consumer.acknowledge(msg)
+ except:
+ # Message failed to be processed
+ consumer.negative_acknowledge(msg)
+
+client.close()
+```
+
+This example shows how to configure negative acknowledgement.
+
+```python
+from pulsar import Client, schema
+
+client = Client('pulsar://localhost:6650')
+
+consumer = client.subscribe('negative_acks','test',schema=schema.StringSchema())
+producer = client.create_producer('negative_acks',schema=schema.StringSchema())
+
+for i in range(10):
+ print('send msg "hello-%d"' % i)
+ producer.send_async('hello-%d' % i, callback=None)
+
+producer.flush()
+
+for i in range(10):
+ msg = consumer.receive()
+ consumer.negative_acknowledge(msg)
+ print('receive and nack msg "%s"' % msg.data())
+
+for i in range(10):
+ msg = consumer.receive()
+ consumer.acknowledge(msg)
+ print('receive and ack msg "%s"' % msg.data())
+
+try:
+ # No more messages expected
+ msg = consumer.receive(100)
+except:
+ print("no more msg")
+ pass
+```
+
+### Reader interface example
+
+You can use the Pulsar Python API to use the Pulsar [reader interface](concepts-clients.md#reader-interface). Here's an example:
+
+```python
+# MessageId taken from a previously fetched message
+msg_id = msg.message_id()
+
+reader = client.create_reader('my-topic', msg_id)
+
+while True:
+ msg = reader.read_next()
+ print("Received message '{}' id='{}'".format(msg.data(), msg.message_id()))
+ # No acknowledgment
+```
+
+
+## Schema
+
+### Declaring and validating schema
+
+A schema can be declared by passing a class that inherits
+from `pulsar.schema.Record` and defines the fields as
+class variables. For example:
+
+```python
+from pulsar.schema import *
+
+class Example(Record):
+ a = String()
+ b = Integer()
+ c = Boolean()
+```
+
+With this simple schema definition we can then create producers,
+consumers and readers instances that will be referring to that.
+
+```python
+producer = client.create_producer(
+ topic='my-topic',
+ schema=AvroSchema(Example) )
+
+producer.send(Example(a='Hello', b=1))
+```
+
+When the producer is created, the Pulsar broker will validate that
+the existing topic schema is indeed of "Avro" type and that the
+format is compatible with the schema definition of the `Example`
+class.
+
+If there is a mismatch, the producer creation will raise an
Review comment:
```suggestion
If there is a mismatch, the producer creation raises an
```
##########
File path: site2/website/versioned_docs/version-2.4.0/client-libraries-python.md
##########
@@ -0,0 +1,283 @@
+---
+id: version-2.4.0-client-libraries-python
+title: The Pulsar Python client
+sidebar_label: Python
+original_id: client-libraries-python
+---
+
+The Pulsar Python client library is a wrapper over the existing [C++ client library](client-libraries-cpp.md) and exposes all of the [same features](/api/cpp). You can find the code in the [`python` subdirectory](https://github.com/apache/pulsar/tree/master/pulsar-client-cpp/python) of the C++ client code.
+
+## Installation
+
+You can install the [`pulsar-client`](https://pypi.python.org/pypi/pulsar-client) library either via [PyPi](https://pypi.python.org/pypi), using [pip](#installation-using-pip), or by building the library from source.
+
+### Installation using pip
+
+To install the `pulsar-client` library as a pre-built package using the [pip](https://pip.pypa.io/en/stable/) package manager:
+
+```shell
+$ pip install pulsar-client=={{pulsar:version_number}}
+```
+
+Installation via PyPi is available for the following Python versions:
+
+Platform | Supported Python versions
+:--------|:-------------------------
+| MacOS<br /> 10.11 (El Capitan) — 10.12 (Sierra) — 10.13 (High Sierra) — 10.14 (Mojave)<br />| 2.7, 3.7
+|Linux | 2.7, 3.4, 3.5, 3.6, 3.7
+
+### Installing from source
+
+To install the `pulsar-client` library by building from source, follow [these instructions](client-libraries-cpp.md#compilation) and compile the Pulsar C++ client library. That will also build the Python binding for the library.
+
+To install the built Python bindings:
+
+```shell
+$ git clone https://github.com/apache/pulsar
+$ cd pulsar/pulsar-client-cpp/python
+$ sudo python setup.py install
+```
+
+## API Reference
+
+The complete Python API reference is available at [api/python](/api/python).
+
+## Examples
+
+Below you'll find a variety of Python code examples for the `pulsar-client` library.
+
+### Producer example
+
+This creates a Python producer for the `my-topic` topic and send 10 messages on that topic:
+
+```python
+import pulsar
+
+client = pulsar.Client('pulsar://localhost:6650')
+
+producer = client.create_producer('my-topic')
+
+for i in range(10):
+ producer.send(('Hello-%d' % i).encode('utf-8'))
+
+client.close()
+```
+
+### Consumer example
+
+This creates a consumer with the `my-subscription` subscription on the `my-topic` topic, listen for incoming messages, print the content and ID of messages that arrive, and acknowledge each message to the Pulsar broker:
+
+```python
+consumer = client.subscribe('my-topic', 'my-subscription')
+
+while True:
+ msg = consumer.receive()
+ try:
+ print("Received message '{}' id='{}'".format(msg.data(), msg.message_id()))
+ # Acknowledge successful processing of the message
+ consumer.acknowledge(msg)
+ except:
+ # Message failed to be processed
+ consumer.negative_acknowledge(msg)
+
+client.close()
+```
+
+This example shows how to configure negative acknowledgement.
+
+```python
+from pulsar import Client, schema
+
+client = Client('pulsar://localhost:6650')
+
+consumer = client.subscribe('negative_acks','test',schema=schema.StringSchema())
+producer = client.create_producer('negative_acks',schema=schema.StringSchema())
+
+for i in range(10):
+ print('send msg "hello-%d"' % i)
+ producer.send_async('hello-%d' % i, callback=None)
+
+producer.flush()
+
+for i in range(10):
+ msg = consumer.receive()
+ consumer.negative_acknowledge(msg)
+ print('receive and nack msg "%s"' % msg.data())
+
+for i in range(10):
+ msg = consumer.receive()
+ consumer.acknowledge(msg)
+ print('receive and ack msg "%s"' % msg.data())
+
+try:
+ # No more messages expected
+ msg = consumer.receive(100)
+except:
+ print("no more msg")
+ pass
+```
+
+### Reader interface example
+
+You can use the Pulsar Python API to use the Pulsar [reader interface](concepts-clients.md#reader-interface). Here's an example:
+
+```python
+# MessageId taken from a previously fetched message
+msg_id = msg.message_id()
+
+reader = client.create_reader('my-topic', msg_id)
+
+while True:
+ msg = reader.read_next()
+ print("Received message '{}' id='{}'".format(msg.data(), msg.message_id()))
+ # No acknowledgment
+```
+
+
+## Schema
+
+### Declaring and validating schema
+
+A schema can be declared by passing a class that inherits
+from `pulsar.schema.Record` and defines the fields as
+class variables. For example:
+
+```python
+from pulsar.schema import *
+
+class Example(Record):
+ a = String()
+ b = Integer()
+ c = Boolean()
+```
+
+With this simple schema definition we can then create producers,
+consumers and readers instances that will be referring to that.
+
+```python
+producer = client.create_producer(
+ topic='my-topic',
+ schema=AvroSchema(Example) )
+
+producer.send(Example(a='Hello', b=1))
+```
+
+When the producer is created, the Pulsar broker will validate that
Review comment:
```suggestion
When the producer is created, the Pulsar broker validates that
```
##########
File path: site2/website/versioned_docs/version-2.4.0/client-libraries-python.md
##########
@@ -0,0 +1,283 @@
+---
+id: version-2.4.0-client-libraries-python
+title: The Pulsar Python client
+sidebar_label: Python
+original_id: client-libraries-python
+---
+
+The Pulsar Python client library is a wrapper over the existing [C++ client library](client-libraries-cpp.md) and exposes all of the [same features](/api/cpp). You can find the code in the [`python` subdirectory](https://github.com/apache/pulsar/tree/master/pulsar-client-cpp/python) of the C++ client code.
+
+## Installation
+
+You can install the [`pulsar-client`](https://pypi.python.org/pypi/pulsar-client) library either via [PyPi](https://pypi.python.org/pypi), using [pip](#installation-using-pip), or by building the library from source.
+
+### Installation using pip
+
+To install the `pulsar-client` library as a pre-built package using the [pip](https://pip.pypa.io/en/stable/) package manager:
+
+```shell
+$ pip install pulsar-client=={{pulsar:version_number}}
+```
+
+Installation via PyPi is available for the following Python versions:
+
+Platform | Supported Python versions
+:--------|:-------------------------
+| MacOS<br /> 10.11 (El Capitan) — 10.12 (Sierra) — 10.13 (High Sierra) — 10.14 (Mojave)<br />| 2.7, 3.7
+|Linux | 2.7, 3.4, 3.5, 3.6, 3.7
+
+### Installing from source
+
+To install the `pulsar-client` library by building from source, follow [these instructions](client-libraries-cpp.md#compilation) and compile the Pulsar C++ client library. That will also build the Python binding for the library.
+
+To install the built Python bindings:
+
+```shell
+$ git clone https://github.com/apache/pulsar
+$ cd pulsar/pulsar-client-cpp/python
+$ sudo python setup.py install
+```
+
+## API Reference
+
+The complete Python API reference is available at [api/python](/api/python).
+
+## Examples
+
+Below you'll find a variety of Python code examples for the `pulsar-client` library.
+
+### Producer example
+
+This creates a Python producer for the `my-topic` topic and send 10 messages on that topic:
+
+```python
+import pulsar
+
+client = pulsar.Client('pulsar://localhost:6650')
+
+producer = client.create_producer('my-topic')
+
+for i in range(10):
+ producer.send(('Hello-%d' % i).encode('utf-8'))
+
+client.close()
+```
+
+### Consumer example
+
+This creates a consumer with the `my-subscription` subscription on the `my-topic` topic, listen for incoming messages, print the content and ID of messages that arrive, and acknowledge each message to the Pulsar broker:
+
+```python
+consumer = client.subscribe('my-topic', 'my-subscription')
+
+while True:
+ msg = consumer.receive()
+ try:
+ print("Received message '{}' id='{}'".format(msg.data(), msg.message_id()))
+ # Acknowledge successful processing of the message
+ consumer.acknowledge(msg)
+ except:
+ # Message failed to be processed
+ consumer.negative_acknowledge(msg)
+
+client.close()
+```
+
+This example shows how to configure negative acknowledgement.
+
+```python
+from pulsar import Client, schema
+
+client = Client('pulsar://localhost:6650')
+
+consumer = client.subscribe('negative_acks','test',schema=schema.StringSchema())
+producer = client.create_producer('negative_acks',schema=schema.StringSchema())
+
+for i in range(10):
+ print('send msg "hello-%d"' % i)
+ producer.send_async('hello-%d' % i, callback=None)
+
+producer.flush()
+
+for i in range(10):
+ msg = consumer.receive()
+ consumer.negative_acknowledge(msg)
+ print('receive and nack msg "%s"' % msg.data())
+
+for i in range(10):
+ msg = consumer.receive()
+ consumer.acknowledge(msg)
+ print('receive and ack msg "%s"' % msg.data())
+
+try:
+ # No more messages expected
+ msg = consumer.receive(100)
+except:
+ print("no more msg")
+ pass
+```
+
+### Reader interface example
+
+You can use the Pulsar Python API to use the Pulsar [reader interface](concepts-clients.md#reader-interface). Here's an example:
+
+```python
+# MessageId taken from a previously fetched message
+msg_id = msg.message_id()
+
+reader = client.create_reader('my-topic', msg_id)
+
+while True:
+ msg = reader.read_next()
+ print("Received message '{}' id='{}'".format(msg.data(), msg.message_id()))
+ # No acknowledgment
+```
+
+
+## Schema
+
+### Declaring and validating schema
+
+A schema can be declared by passing a class that inherits
+from `pulsar.schema.Record` and defines the fields as
+class variables. For example:
+
+```python
+from pulsar.schema import *
+
+class Example(Record):
+ a = String()
+ b = Integer()
+ c = Boolean()
+```
+
+With this simple schema definition we can then create producers,
+consumers and readers instances that will be referring to that.
+
+```python
+producer = client.create_producer(
+ topic='my-topic',
+ schema=AvroSchema(Example) )
+
+producer.send(Example(a='Hello', b=1))
+```
+
+When the producer is created, the Pulsar broker will validate that
+the existing topic schema is indeed of "Avro" type and that the
+format is compatible with the schema definition of the `Example`
+class.
+
+If there is a mismatch, the producer creation will raise an
+exception.
+
+Once a producer is created with a certain schema definition,
+it will only accept objects that are instances of the declared
Review comment:
```suggestion
it only accepts objects that are instances of the declared
```
##########
File path: site2/website/versioned_docs/version-2.4.0/client-libraries-python.md
##########
@@ -0,0 +1,283 @@
+---
+id: version-2.4.0-client-libraries-python
+title: The Pulsar Python client
+sidebar_label: Python
+original_id: client-libraries-python
+---
+
+The Pulsar Python client library is a wrapper over the existing [C++ client library](client-libraries-cpp.md) and exposes all of the [same features](/api/cpp). You can find the code in the [`python` subdirectory](https://github.com/apache/pulsar/tree/master/pulsar-client-cpp/python) of the C++ client code.
+
+## Installation
+
+You can install the [`pulsar-client`](https://pypi.python.org/pypi/pulsar-client) library either via [PyPi](https://pypi.python.org/pypi), using [pip](#installation-using-pip), or by building the library from source.
+
+### Installation using pip
+
+To install the `pulsar-client` library as a pre-built package using the [pip](https://pip.pypa.io/en/stable/) package manager:
+
+```shell
+$ pip install pulsar-client=={{pulsar:version_number}}
+```
+
+Installation via PyPi is available for the following Python versions:
+
+Platform | Supported Python versions
+:--------|:-------------------------
+| MacOS<br /> 10.11 (El Capitan) — 10.12 (Sierra) — 10.13 (High Sierra) — 10.14 (Mojave)<br />| 2.7, 3.7
+|Linux | 2.7, 3.4, 3.5, 3.6, 3.7
+
+### Installing from source
+
+To install the `pulsar-client` library by building from source, follow [these instructions](client-libraries-cpp.md#compilation) and compile the Pulsar C++ client library. That will also build the Python binding for the library.
+
+To install the built Python bindings:
+
+```shell
+$ git clone https://github.com/apache/pulsar
+$ cd pulsar/pulsar-client-cpp/python
+$ sudo python setup.py install
+```
+
+## API Reference
+
+The complete Python API reference is available at [api/python](/api/python).
+
+## Examples
+
+Below you'll find a variety of Python code examples for the `pulsar-client` library.
+
+### Producer example
+
+This creates a Python producer for the `my-topic` topic and send 10 messages on that topic:
+
+```python
+import pulsar
+
+client = pulsar.Client('pulsar://localhost:6650')
+
+producer = client.create_producer('my-topic')
+
+for i in range(10):
+ producer.send(('Hello-%d' % i).encode('utf-8'))
+
+client.close()
+```
+
+### Consumer example
+
+This creates a consumer with the `my-subscription` subscription on the `my-topic` topic, listen for incoming messages, print the content and ID of messages that arrive, and acknowledge each message to the Pulsar broker:
Review comment:
```suggestion
This example creates a consumer with the `my-subscription` subscription on the `my-topic` topic, listens for incoming messages, prints the content and ID of messages that arrive, and acknowledges each message to the Pulsar broker:
```
##########
File path: site2/website/versioned_docs/version-2.4.0/client-libraries-python.md
##########
@@ -0,0 +1,283 @@
+---
+id: version-2.4.0-client-libraries-python
+title: The Pulsar Python client
+sidebar_label: Python
+original_id: client-libraries-python
+---
+
+The Pulsar Python client library is a wrapper over the existing [C++ client library](client-libraries-cpp.md) and exposes all of the [same features](/api/cpp). You can find the code in the [`python` subdirectory](https://github.com/apache/pulsar/tree/master/pulsar-client-cpp/python) of the C++ client code.
+
+## Installation
+
+You can install the [`pulsar-client`](https://pypi.python.org/pypi/pulsar-client) library either via [PyPi](https://pypi.python.org/pypi), using [pip](#installation-using-pip), or by building the library from source.
+
+### Installation using pip
+
+To install the `pulsar-client` library as a pre-built package using the [pip](https://pip.pypa.io/en/stable/) package manager:
+
+```shell
+$ pip install pulsar-client=={{pulsar:version_number}}
+```
+
+Installation via PyPi is available for the following Python versions:
+
+Platform | Supported Python versions
+:--------|:-------------------------
+| MacOS<br /> 10.11 (El Capitan) — 10.12 (Sierra) — 10.13 (High Sierra) — 10.14 (Mojave)<br />| 2.7, 3.7
+|Linux | 2.7, 3.4, 3.5, 3.6, 3.7
+
+### Installing from source
+
+To install the `pulsar-client` library by building from source, follow [these instructions](client-libraries-cpp.md#compilation) and compile the Pulsar C++ client library. That will also build the Python binding for the library.
+
+To install the built Python bindings:
+
+```shell
+$ git clone https://github.com/apache/pulsar
+$ cd pulsar/pulsar-client-cpp/python
+$ sudo python setup.py install
+```
+
+## API Reference
+
+The complete Python API reference is available at [api/python](/api/python).
+
+## Examples
+
+Below you'll find a variety of Python code examples for the `pulsar-client` library.
+
+### Producer example
+
+This creates a Python producer for the `my-topic` topic and send 10 messages on that topic:
+
+```python
+import pulsar
+
+client = pulsar.Client('pulsar://localhost:6650')
+
+producer = client.create_producer('my-topic')
+
+for i in range(10):
+ producer.send(('Hello-%d' % i).encode('utf-8'))
+
+client.close()
+```
+
+### Consumer example
+
+This creates a consumer with the `my-subscription` subscription on the `my-topic` topic, listen for incoming messages, print the content and ID of messages that arrive, and acknowledge each message to the Pulsar broker:
+
+```python
+consumer = client.subscribe('my-topic', 'my-subscription')
+
+while True:
+ msg = consumer.receive()
+ try:
+ print("Received message '{}' id='{}'".format(msg.data(), msg.message_id()))
+ # Acknowledge successful processing of the message
+ consumer.acknowledge(msg)
+ except:
+ # Message failed to be processed
+ consumer.negative_acknowledge(msg)
+
+client.close()
+```
+
+This example shows how to configure negative acknowledgement.
+
+```python
+from pulsar import Client, schema
+
+client = Client('pulsar://localhost:6650')
+
+consumer = client.subscribe('negative_acks','test',schema=schema.StringSchema())
+producer = client.create_producer('negative_acks',schema=schema.StringSchema())
+
+for i in range(10):
+ print('send msg "hello-%d"' % i)
+ producer.send_async('hello-%d' % i, callback=None)
+
+producer.flush()
+
+for i in range(10):
+ msg = consumer.receive()
+ consumer.negative_acknowledge(msg)
+ print('receive and nack msg "%s"' % msg.data())
+
+for i in range(10):
+ msg = consumer.receive()
+ consumer.acknowledge(msg)
+ print('receive and ack msg "%s"' % msg.data())
+
+try:
+ # No more messages expected
+ msg = consumer.receive(100)
+except:
+ print("no more msg")
+ pass
+```
+
+### Reader interface example
+
+You can use the Pulsar Python API to use the Pulsar [reader interface](concepts-clients.md#reader-interface). Here's an example:
+
+```python
+# MessageId taken from a previously fetched message
+msg_id = msg.message_id()
+
+reader = client.create_reader('my-topic', msg_id)
+
+while True:
+ msg = reader.read_next()
+ print("Received message '{}' id='{}'".format(msg.data(), msg.message_id()))
+ # No acknowledgment
+```
+
+
+## Schema
+
+### Declaring and validating schema
+
+A schema can be declared by passing a class that inherits
+from `pulsar.schema.Record` and defines the fields as
+class variables. For example:
+
+```python
+from pulsar.schema import *
+
+class Example(Record):
+ a = String()
+ b = Integer()
+ c = Boolean()
+```
+
+With this simple schema definition we can then create producers,
+consumers and readers instances that will be referring to that.
+
+```python
+producer = client.create_producer(
+ topic='my-topic',
+ schema=AvroSchema(Example) )
+
+producer.send(Example(a='Hello', b=1))
+```
+
+When the producer is created, the Pulsar broker will validate that
+the existing topic schema is indeed of "Avro" type and that the
+format is compatible with the schema definition of the `Example`
+class.
+
+If there is a mismatch, the producer creation will raise an
+exception.
+
+Once a producer is created with a certain schema definition,
+it will only accept objects that are instances of the declared
+schema class.
+
+Similarly, for a consumer/reader, the consumer will return an
Review comment:
```suggestion
Similarly, for a consumer/reader, the consumer returns an
```
##########
File path: site2/website/versioned_docs/version-2.4.0/client-libraries-python.md
##########
@@ -0,0 +1,283 @@
+---
+id: version-2.4.0-client-libraries-python
+title: The Pulsar Python client
+sidebar_label: Python
+original_id: client-libraries-python
+---
+
+The Pulsar Python client library is a wrapper over the existing [C++ client library](client-libraries-cpp.md) and exposes all of the [same features](/api/cpp). You can find the code in the [`python` subdirectory](https://github.com/apache/pulsar/tree/master/pulsar-client-cpp/python) of the C++ client code.
+
+## Installation
+
+You can install the [`pulsar-client`](https://pypi.python.org/pypi/pulsar-client) library either via [PyPi](https://pypi.python.org/pypi), using [pip](#installation-using-pip), or by building the library from source.
+
+### Installation using pip
+
+To install the `pulsar-client` library as a pre-built package using the [pip](https://pip.pypa.io/en/stable/) package manager:
+
+```shell
+$ pip install pulsar-client=={{pulsar:version_number}}
+```
+
+Installation via PyPi is available for the following Python versions:
+
+Platform | Supported Python versions
+:--------|:-------------------------
+| MacOS<br /> 10.11 (El Capitan) — 10.12 (Sierra) — 10.13 (High Sierra) — 10.14 (Mojave)<br />| 2.7, 3.7
+|Linux | 2.7, 3.4, 3.5, 3.6, 3.7
+
+### Installing from source
+
+To install the `pulsar-client` library by building from source, follow [these instructions](client-libraries-cpp.md#compilation) and compile the Pulsar C++ client library. That will also build the Python binding for the library.
+
+To install the built Python bindings:
+
+```shell
+$ git clone https://github.com/apache/pulsar
+$ cd pulsar/pulsar-client-cpp/python
+$ sudo python setup.py install
+```
+
+## API Reference
+
+The complete Python API reference is available at [api/python](/api/python).
+
+## Examples
+
+Below you'll find a variety of Python code examples for the `pulsar-client` library.
+
+### Producer example
+
+This creates a Python producer for the `my-topic` topic and send 10 messages on that topic:
+
+```python
+import pulsar
+
+client = pulsar.Client('pulsar://localhost:6650')
+
+producer = client.create_producer('my-topic')
+
+for i in range(10):
+ producer.send(('Hello-%d' % i).encode('utf-8'))
+
+client.close()
+```
+
+### Consumer example
+
+This creates a consumer with the `my-subscription` subscription on the `my-topic` topic, listen for incoming messages, print the content and ID of messages that arrive, and acknowledge each message to the Pulsar broker:
+
+```python
+consumer = client.subscribe('my-topic', 'my-subscription')
+
+while True:
+ msg = consumer.receive()
+ try:
+ print("Received message '{}' id='{}'".format(msg.data(), msg.message_id()))
+ # Acknowledge successful processing of the message
+ consumer.acknowledge(msg)
+ except:
+ # Message failed to be processed
+ consumer.negative_acknowledge(msg)
+
+client.close()
+```
+
+This example shows how to configure negative acknowledgement.
+
+```python
+from pulsar import Client, schema
+
+client = Client('pulsar://localhost:6650')
+
+consumer = client.subscribe('negative_acks','test',schema=schema.StringSchema())
+producer = client.create_producer('negative_acks',schema=schema.StringSchema())
+
+for i in range(10):
+ print('send msg "hello-%d"' % i)
+ producer.send_async('hello-%d' % i, callback=None)
+
+producer.flush()
+
+for i in range(10):
+ msg = consumer.receive()
+ consumer.negative_acknowledge(msg)
+ print('receive and nack msg "%s"' % msg.data())
+
+for i in range(10):
+ msg = consumer.receive()
+ consumer.acknowledge(msg)
+ print('receive and ack msg "%s"' % msg.data())
+
+try:
+ # No more messages expected
+ msg = consumer.receive(100)
+except:
+ print("no more msg")
+ pass
+```
+
+### Reader interface example
+
+You can use the Pulsar Python API to use the Pulsar [reader interface](concepts-clients.md#reader-interface). Here's an example:
+
+```python
+# MessageId taken from a previously fetched message
+msg_id = msg.message_id()
+
+reader = client.create_reader('my-topic', msg_id)
+
+while True:
+ msg = reader.read_next()
+ print("Received message '{}' id='{}'".format(msg.data(), msg.message_id()))
+ # No acknowledgment
+```
+
+
+## Schema
+
+### Declaring and validating schema
+
+A schema can be declared by passing a class that inherits
+from `pulsar.schema.Record` and defines the fields as
+class variables. For example:
+
+```python
+from pulsar.schema import *
+
+class Example(Record):
+ a = String()
+ b = Integer()
+ c = Boolean()
+```
+
+With this simple schema definition we can then create producers,
+consumers and readers instances that will be referring to that.
+
+```python
+producer = client.create_producer(
+ topic='my-topic',
+ schema=AvroSchema(Example) )
+
+producer.send(Example(a='Hello', b=1))
+```
+
+When the producer is created, the Pulsar broker will validate that
+the existing topic schema is indeed of "Avro" type and that the
+format is compatible with the schema definition of the `Example`
+class.
+
+If there is a mismatch, the producer creation will raise an
+exception.
+
+Once a producer is created with a certain schema definition,
+it will only accept objects that are instances of the declared
Review comment:
pls check all
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