Introduction

This package provides a client interface to query Trino a distributed SQL engine. It supports Python>=3.6 and pypy.

Installation

$ pip install trino

Quick Start

Use the DBAPI interface to query Trino:

import trino
conn = trino.dbapi.connect(
    host='localhost',
    port=8080,
    user='the-user',
    catalog='the-catalog',
    schema='the-schema',
)
cur = conn.cursor()
cur.execute('SELECT * FROM system.runtime.nodes')
rows = cur.fetchall()

This will query the system.runtime.nodes system tables that shows the nodes in the Trino cluster.

The DBAPI implementation in trino.dbapi provides methods to retrieve fewer rows for example Cursor.fetchone() or Cursor.fetchmany(). By default Cursor.fetchmany() fetches one row. Please set trino.dbapi.Cursor.arraysize accordingly.

Basic Authentication

The BasicAuthentication class can be used to connect to a Trino cluster configured with the Password file authentication type, LDAP authentication type or Salesforce authentication type:

import trino
conn = trino.dbapi.connect(
    host='coordinator url',
    port=8443,
    user='the-user',
    catalog='the-catalog',
    schema='the-schema',
    http_scheme='https',
    auth=trino.auth.BasicAuthentication("principal id", "password"),
)
cur = conn.cursor()
cur.execute('SELECT * FROM system.runtime.nodes')
rows = cur.fetchall()

JWT Authentication

The JWTAuthentication class can be used to connect to a Trino cluster configured with the JWT authentication type:

import trino
JWT_TOKEN = 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJuYW1lIjoiSm9obiBEb2UifQ.DjwRE2jZhren2Wt37t5hlVru6Myq4AhpGLiiefF69u8'
conn = trino.dbapi.connect(
    host='coordinator-url',
    port=8443,
    user='the-user',
    catalog='the-catalog',
    schema='the-schema',
    http_scheme='https',
    auth=trino.auth.JWTAuthentication(JWT_TOKEN),
)
cur = conn.cursor()
cur.execute('SELECT * FROM system.runtime.nodes')
rows = cur.fetchall()

OAuth2 Authentication

OAuth2Authentication class can be used to connect to a Trino cluster configured with the OAUTH2 authentication type:
A callback to handle the redirect url can be provided via param redirect_auth_url_handler, by default it just outputs the redirect url to stdout

import trino
conn = trino.dbapi.connect(
    host='coordinator-url',
    port=8443,
    user='the-user',
    catalog='the-catalog',
    schema='the-schema',
    http_scheme='https',
    auth=trino.auth.OAuth2Authentication(),
)
cur = conn.cursor()
cur.execute('SELECT * FROM system.runtime.nodes')
rows = cur.fetchall()

Transactions

The client runs by default in autocommit mode. To enable transactions, set isolation_level to a value different than IsolationLevel.AUTOCOMMIT:

import trino
from trino import transaction
with trino.dbapi.connect(
    host='localhost',
    port=8080,
    user='the-user',
    catalog='the-catalog',
    schema='the-schema',
    isolation_level=transaction.IsolationLevel.REPEATABLE_READ,
) as conn:
  cur = conn.cursor()
  cur.execute('INSERT INTO sometable VALUES (1, 2, 3)')
  cur.fetchall()
  cur.execute('INSERT INTO sometable VALUES (4, 5, 6)')
  cur.fetchall()

The transaction is created when the first SQL statement is executed. trino.dbapi.Connection.commit() will be automatically called when the code exits the with context and the queries succeed, otherwise trino.dbapi.Connection.rollback() will be called.

Development

Getting Started With Development

Start by forking the repository and then modify the code in your fork.

Clone the repository and go inside the code directory. Then you can get the version with ./setup.py --version.

We recommend that you use Python3's venv for development:

$ python3 -m venv .venv
$ . .venv/bin/activate
$ pip install .

For development purpose, pip can reference the code you are modifying in a virtual env:

$ pip install -e .
# To additionally install all dependencies for development run below command
$ pip install -e '.[tests]'

That way, you do not need to run pip install again to make your changes applied to the virtual env.

When the code is ready, submit a Pull Request.

Code Style

For Python code, adhere to PEP 8.
Prefer code that is readable over one that is "clever".
When writing a Git commit message, follow these guidelines.

Running Tests

trino-python-client uses pytest for its tests. To run only unit tests, type:

$ pytest tests/unit

Then you can pass options like --pdb or anything supported by pytest --help.

To run the tests with different versions of Python in managed virtual envs, use tox (see the configuration in tox.ini):

$ tox

To run integration tests:

$ pytest tests/integration

They pull a Docker image and then run a container with a Trino server:

the image is named trinodb/trino:${TRINO_VERSION}
the container is named trino-python-client-tests-{uuid4()[:7]}

Releasing

Set up your development environment.
Check the local workspace is up to date and has no uncommitted changes
```
git fetch -a && git status
```
Change version in trino/__init__.py to a new version, e.g. 0.123.0.

Commit

git commit -a -m "Bump version to 0.123.0"

Create an annotated tag
```
git tag -m "" 0.123.0
```

Create release package and upload it to PyPI

. .venv/bin/activate &&
pip install twine &&
rm -rf dist/ &&
./setup.py sdist bdist_wheel &&
twine upload dist/* &&
open https://pypi.org/project/trino/ &&
echo "Released!"

Push the branch and the tag
```
git push upstream master 0.123.0
```
Send release announcement.

Need Help?

Feel free to create an issue as it make your request visible to other users and contributors.

If an interactive discussion would be better or if you just want to hangout and chat about the Trino Python client, you can join us on the #python-client channel on Trino Slack.

long2ice / trino-python-client