db-utils 0.2.93

Helper class to connect to Redshift, Snowflake, DynamoDB and S3

db_utils library

Installation

pip install db_utils

pg_connect class (previously DBUtil)

A database connection class to interact with Postgres or Redshift

Basic Usage:

• create database configuration file
• example below is called .databases.conf

    [redshift_example]
    host=redshift.example.com
    user=test_user
    password=password
    port=5439
    database=test_db

    >>> from db_utils.pg_connect import pg_connect
    >>>
    >>> db = pg_connect('redshift_example', '.databases.conf')
    >>> db.get_arr_from_query('select * from test', pprint=True)

snowflake_connect class

A database connection class to interact with snowflake

Basic Usage:

• create database configuration file
• example below is called .databases.conf

    [snowflake]
    account=abc123.us-east-1
    host=abc123.us-east-1.snowflakecomputing.com
    user=test_user
    password=password
    port=443
    database=test_db
    aws_access_key_id=<key_id>
    aws_secret_access_key=<secret_key>

snowflake_s3 class

A child class of snowflake_connect class used to retrieve large datasets in small chunks

Basic Usage:

• create database configuration file
• example below is called .databases.conf
• note the additional fields required

    [snowflake]
    account=abc123.us-east-1
    host=abc123.us-east-1.snowflakecomputing.com
    user=test_user
    password=password
    port=443
    database=test_db
    aws_access_key_id=<key_id>
    aws_secret_access_key=<secret_key>
    default_bucket=

example) Loading large data set into memory in chunks

    >>> from db_utils.snowflake_connect import snowflake_s3
    >>> import os
    >>>
    >>> file_format = '''
    TYPE = CSV
    COMPRESSION = NONE
    '''
    >>>
    >>>
    >>> with snowflake_s3('snowflake', '.databases.conf') as db:
    >>>     db.cursor('SELECT * FROM example_large_table', file_format=file_format, pprint=True)
    >>>
    >>>     while True:
    >>>         file = db.fetch(contents=True)
    >>>
    >>>         if file:
    >>>             for row in file:
    >>>                 print(row)
    >>>
    >>>         else:
    >>>             break

db_connect class

Parent python database connectin class utilizing API specification v2.0 https://www.python.org/dev/peps/pep-0249/#connection-methods use the connection classes above specific to the flavor of db you're using

s3_connect class

Connection library for interacting with S3

Basic Usage:

• add s3 section to .databases.conf file (created in previous example)

    [s3]
        aws_access_key_id=<key_id>
        aws_secret_access_key=<secret_key>
        default_bucket=<bucket>


    >>> from db_utils.s3_connect import s3_connect
    >>>
    >>> s3 = s3_connect('.databases.conf', 's3')
    >>> s3.list_keys(prefix='examples')

example) grab file from s3 into memory as stringIO object

    >>> from db_utils.s3_connect import s3_connect
    >>>
    >>> s3 = s3_connect('.databases.conf', 's3')
    >>> s3.get_contents('example_file', stringIO=True)
    >>> s3.read()

dynamodb_connect class

Connection library for interacting with Dynamodb

timer class

Helper class to time long running processes

Basic Usage:

>>> from db_utils.timer import timer
>>>
>>> t = timer()
>>> t.lap('s')
5.469961