How to use SDK

1. Example

You must replace user information, such as image_id, access_key_id, and access_key_secret, and OSS-related directories in the codes.

import time
from batchcompute import Cient, ClientError
from batchcompute import CN_SHENZHEN as REGION
from batchcompute.resources import (
    JobDescription, TaskDescription, DAG,
    GroupDescription, ClusterDescription,
)
# some other codes here
access_key_id = ... # your AccessKey id
access_key_secret = ... # your AccessKey secret
image_id = ... # the id of a image created before
instance_type = ... # instance type
client = Client(REGION, access_key_id, access_key_secret)
try: 
    # Create cluster.
    cluster_desc = ClusterDescription()
    group_desc = GroupDescription()
    group_desc.DesiredVMCount = 1
    group_desc.InstanceType = instance_type
    cluster_desc.add_group('group1', group_desc)
    cluster_desc.Name = "BatchcomputeCluster" 
    cluster_desc.ImageId = image_id 
    cluster_desc.Description = "Python SDK test" 
    cluster_id = client.create_cluster(cluster_desc).Id
    # Create job.
    job_desc = JobDescription()
    echo_task = TaskDescription()
    # Create map task.
    echo_task.Parameters.Command.CommandLine = "echo Batchcompute service"
    echo_task.Parameters.Command.PackagePath = ""
    echo_task.Parameters.StdoutRedirectPath = "oss://xxx/xxx/"  # Better replace this path
    echo_task.Parameters.StderrRedirectPath = "oss://xxx/xxx/"  # Better replace this path 
    echo_task.InstanceCount = 3
    echo_task.ClusterId = cluster_id
    # Create task dag.
    task_dag = DAG()
    task_dag.add_task(task_name="Echo", task=echo_task)
    # Create job description.
    job_desc.DAG = task_dag
    job_desc.Priority = 99 # 0-1000
    job_desc.Name = "PythonSDKDemo" 
    job_desc.JobFailOnInstanceFail = True
    job_id = client.create_job(job_desc).Id
    # Wait for job finished.
    errs = client.poll(job_id)
    if errs: print ("Some errors occur: %s" % '\n'.join(errs))
    # Delete cluster
    client.delete_cluster(cluster_id)
except ClientError, e:
    print (e.get_status_code(), e.get_code(), e.get_requestid(), e.get_msg())

2. Classes and constants

2.1 Interface class

The interface class provides Python implementation for all APIs of the BatchCompute service and some useful auxiliary interfaces.

2.2 Description class

The description class provides parameter classes when resources are created, or returns classes of the service when resource status information is obtained.

About serialization

The description class is a serializable class. All serializable classes in the SDK are inherited from the internal class Jsonizable.The following describes the Jsonizable class and its subclasses.

Parameter description:

Jsonizable and its subclass objects can be initialized by using the dictionaries, Jsonizable objects, or JSON strings that describe the dictionary.Note that all invalid attribute descriptions in the dictionary or JSON strings are discarded when Jsonizable and its subclass objects are initialized.

• Use a dictionary to initialize the Jsonizable class.

e.g.

from batchcompute.resources import JobDescription
# A dict object.
properties = {
    "Name": "PythonSDKDemo",
    "Description": "Batchcompute"
}
jsonizable = JobDescription(properties)
print (jsonizable.Name)
print (jsonizable.Description)

• Use a JSON string to initialize the Jsonizable class.

e.g.

from batchcompute.resources import JobDescription
# A string jsonized from a dict object.
properties = '''{
    "Name": "PythonSDKDemo",
    "Description": "Batchcompute"
}'''
jsonizable = JobDescription(properties)
print (jsonizable.Name)
print (jsonizable.Description)

• Use an object of the same class to initialize the Jsonizable class.

e.g.

form batchcompute.resources import JobDescription
# A JobDescription object.
jsonizable1 = JobDescription()
jsonizable1.Name = "PythonSDKDemo"
jsonizable1.Description = "Batchcompute"
jsonizable2 = JobDescription(jsonizable1)
print(jsonizable2.Name)
print(jsonizable2.Description)

Method description:

About class attributes

All serializable classes contain various attributes. These attributes can be directly read by name. For example, you can use the following code to obtain a job ID:Attribute naming rules are consistent with the class naming rules of the Python specifications PEP8, and different from naming rules of class methods. Attribute names comply with the spelling rules of CamelCase.

# job is a Job object.
job = ...
job_id = job.Id
print (job_id)

• In addition, you can obtain attributes by assigning dictionary values. For example:

# job is a Job object.
job = ...
job_id = job["Id"]
print (job_id)

• For the classes like JobDescription, DAG, and TaskDescription, you can change the value of an attribute by assigning a value. For example:

from batchcompute.resources import JobDescription
job_desc = JobDescription()
job_desc.Name = "PythonSDKDemo"

• For the classes like JobDescription, DAG, and TaskDescription, you can assign a value for a class attribute using a dictionary. For example:

from batchcompute.resources import JobDescription
job_desc = JobDescription()
job_desc["Id"] = "PythonSDKDemo"

2.3 Response class

About the response class

All the response classes, including CreateResponse, GetResponse, ActionRespnse, and ListResponse, are inherited from the internal class RawResponse.The following descriptions are applicable to all RawResponse subclasses.

Attribute description:

e.g.

...
response = client.create_job(job_desc)
print (response.RequestId)
print (response.StatusCode)

2.4 Error class

An exception is thrown when a parameter or request is invalid.

2.5 Constants