0.4.2 breaks some of the older query interfaces (row_handler callback, and connection.query). It replaces the row_handler callback with an iterate() method. Please see examples below
vertica-python is a native Python adapter for the Vertica (http://www.vertica.com) database.
vertica-python is currently in alpha stage; it has been tested for functionality, but does not have a test suite. Please use with caution, and feel free to submit issues and/or pull requests.
vertica-python has been tested with Vertica 6.1.2/7.0.0+ and Python 2.6/2.7.
If you're using pip >= 1.4 and you don't already have pytz installed:
pip install --pre pytz
To install vertica-python with pip:
pip install vertica-python
To install vertica-python with pip (with optional namedparams dependencies):
# see 'Using named parameters' section below
pip install 'vertica-python[namedparams]'
Source code for vertica-python can be found at:
http://github.com/uber/vertica-python
Stream results:
from vertica_python import connect
with vertica_python.connect({'host': '127.0.0.1',
'port': 5433,
'user': 'some_user',
'password': 'some_password',
'database': 'a_database'}) as connection:
cur = connection.cursor()
cur.execute("SELECT * FROM a_table LIMIT 2")
for row in cur.iterate():
print(row)
# {'id': 1, 'value': 'something'}
# {'id': 2, 'value': 'something_else'}Streaming is recommended if you want to further process each row, save the results in a non-list/dict format (e.g. Pandas DataFrame), or save the results in a file.
In-memory results as list:
with vertica_python.connect(...) as connection:
cur = connection.cursor()
cur.execute("SELECT * FROM a_table LIMIT 2")
cur.fetchall()
# [ [1, 'something'], [2, 'something_else'] ]In-memory results as dictionary:
with vertica_python.connect(...) as connection:
cur = connection.cursor('dict')
cur.execute("SELECT * FROM a_table LIMIT 2")
cur.fetchall()
# [ {'id': 1, 'value': 'something'}, {'id': 2, 'value': 'something_else'} ]
connection.close()Using named parameters :
# Using named parameter bindings requires psycopg2>=2.5.1 which is not includes with the base vertica_python requirements.
cur = connection.cursor()
cur.execute("SELECT * FROM a_table WHERE a = :propA b = :propB", {'propA': 1, 'propB': 'stringValue'})
cur.fetchall()
# [ [1, 'something'], [2, 'something_else'] ]Copy :
cur = connection.cursor()
cur.copy("COPY test_copy (id, name) from stdin DELIMITER ',' ", "1,foo\n2,bar")
# input stream copy is todoMIT License, please see LICENSE for details.
Many thanks go to the contributors to the Ruby Vertica gem (https://github.com/sprsquish/vertica), since they did all of the wrestling with Vertica's protocol and have kept the gem updated. They are: