ploomber.clients.DBAPIClient¶

class ploomber.clients.DBAPIClient(connect_fn, connect_kwargs, split_source=None)¶

A client for a PEP 249 compliant client library

Parameters

connect_fn (callable) – The function to use to open the connection
connect_kwargs (dict) – Keyword arguments to pass to connect_fn
split_source (str, optional) – Some database drivers do not support multiple commands in a single execute statement. Use this optiion to split commands by a given character (e.g. ‘;’) and send them one at a time. Defaults to None (no splitting)

Examples

Spec API:

Given the following clients.py:

import sqlite3
from ploomber.clients import DBAPIClient

def get():
    return DBAPIClient(sqlite3.connect, dict(database='my.db'))

Spec API (dag-level client):

clients:
    # key is a task class such as SQLDump or SQLScript
    SQLDump: clients.get

tasks:
    - source: query.sql
      product: output/data.csv

Spec API (task-level client):

tasks:
    - source: query.sql
      product: output/data.csv
      client: clients.get

Python API (dag-level client):

>>> import sqlite3
>>> import pandas as pd
>>> from ploomber import DAG
>>> from ploomber.products import File
>>> from ploomber.tasks import SQLDump
>>> from ploomber.clients import DBAPIClient
>>> con_raw = sqlite3.connect(database='my.db')
>>> df = pd.DataFrame({'a': range(100), 'b': range(100)})
>>> _ = df.to_sql('numbers', con_raw, index=False)
>>> con_raw.close()
>>> dag = DAG()
>>> client = DBAPIClient(sqlite3.connect, dict(database='my.db'))
>>> dag.clients[SQLDump] = client # dag-level client
>>> _ = SQLDump('SELECT * FROM numbers', File('data.parquet'),
...             dag=dag, name='dump',
...             client=client,
...             chunksize=None) # no need to pass client here
>>> _ = dag.build()
>>> df = pd.read_parquet('data.parquet')
>>> df.head(3)
   a  b
0  0  0
1  1  1
2  2  2

Python API (task-level client):

>>> import sqlite3
>>> import pandas as pd
>>> from ploomber import DAG
>>> from ploomber.products import File
>>> from ploomber.tasks import SQLDump
>>> from ploomber.clients import DBAPIClient
>>> con_raw = sqlite3.connect(database='some.db')
>>> df = pd.DataFrame({'a': range(100), 'b': range(100)})
>>> _ = df.to_sql('numbers', con_raw, index=False)
>>> con_raw.close()
>>> dag = DAG()
>>> client = DBAPIClient(sqlite3.connect, dict(database='some.db'))
>>> _ = SQLDump('SELECT * FROM numbers', File('data.parquet'),
...             dag=dag, name='dump',
...             client=client,  # pass client to task
...             chunksize=None)
>>> _ = dag.build()
>>> df = pd.read_parquet('data.parquet')
>>> df.head(3)
   a  b
0  0  0
1  1  1
2  2  2

`close`()	Close connection if there is an active one
`cursor`()
`execute`(code)	Execute code with the existing connection

Contents

ploomber.clients.DBAPIClient¶