Use a Python client to submit a Presto job - E-MapReduce

This topic describes how to use a Python client to access Trino on ACK and perform query operations.

Background information

For more information about Trino Java DataBase Connectivity (JDBC) and related parameters, see trino-python-client.

Prerequisites

A Presto cluster is created on the EMR on ACK page of the new E-MapReduce (EMR) console. For more information, see Getting started.
The AliyunOSSFullAccess and AliyunDLFFullAccess policies are attached to your account. For more information, see Grant permissions to a role.
Python, pip, Trino Python Database API (DBAPI), or SQLAlchemy is installed in the development environment. For more information, see Environment requirements.

Use Trino DBAPI to access Trino on ACK

Note

URL: You can obtain the URL that is used to access the Trino web UI on the Access Links and Ports tab. Then, change trino in the URL to trino-cli.
Username and password: The default username admin and the password that you configured for the user are used.

Sample DBAPI.python file:

from trino.dbapi import connect
from trino.auth import BasicAuthentication

conn = connect(
    port=443,
    # The URL.
    host="trino-cli.c-xxx.xxx.cn-hangzhou.alicontainer.com",
    # The username and password.
    auth=BasicAuthentication("xxx", "xxx"),
    http_scheme="https",
    verify=False
)
cur = conn.cursor()
cur.execute("show catalogs")
rows = cur.fetchall()

Use SQLAlchemy to access Trino on ACK

Note

URL: You can obtain the URL that is used to access the Trino web UI on the Access Links and Ports tab. Then, change trino in the URL to trino-cli.
Username and password: The default username admin and the password that you configured for the user are used.

Sample SQLAlchemy.python file:

from sqlalchemy import create_engine
from sqlalchemy.sql.expression import text
from trino.auth import BasicAuthentication

engine = create_engine(
    # The URL.
    "trino://trino-cli.c-xxx.xxx.cn-hangzhou.alicontainer.com:443",
    connect_args={
        # The username and password.
        "auth": BasicAuthentication("xxx", "xxx"),
        "http_scheme": "https",
        "verify": False,
    }
)
connection = engine.connect()

rows = connection.execute(text("show catalogs")).fetchall()