Python

Sample database configuration

This section describes the configuration of a sample database that allows remote connections:

credentials:
  users:
    sampleuser:
      password: '123456'
      privileges:
      - permissions: [ read, write ]
        spaces: [ bands ]
      - permissions: [ execute ]
        functions: [ get_bands_older_than ]

groups:
  group001:
    replicasets:
      replicaset001:
        instances:
          instance001:
            iproto:
              listen:
              - uri: '127.0.0.1:3301'

app:
  file: 'myapp.lua'

• The configuration contains one instance that listens for incoming requests on the 127.0.0.1:3301 address.
• sampleuser has privileges to select and modify data in the bands space and execute the get_bands_older_than stored function. This user can be used to connect to the instance remotely.
• myapp.lua defines the data model and a stored function.

The myapp.lua file looks as follows:

-- Create a space --
box.schema.space.create('bands')

-- Specify field names and types --
box.space.bands:format({
    { name = 'id', type = 'unsigned' },
    { name = 'band_name', type = 'string' },
    { name = 'year', type = 'unsigned' }
})

-- Create indexes --
box.space.bands:create_index('primary', { parts = { 'id' } })
box.space.bands:create_index('band', { parts = { 'band_name' } })
box.space.bands:create_index('year_band', { parts = { { 'year' }, { 'band_name' } } })

-- Create a stored function --
box.schema.func.create('get_bands_older_than', {
    body = [[
    function(year)
        return box.space.bands.index.year_band:select({ year }, { iterator = 'LT', limit = 10 })
    end
    ]]
})

You can find the full example on GitHub: sample_db.

Starting a sample database application

Before creating and starting a client Python application, you need to run the sample_db application using tt start:

$ tt start sample_db

Now you can create a client Python application that makes requests to this database.

Developing a client application

Before you start, make sure you have Python installed on your computer.

import tarantool

# Connect to the database
conn = tarantool.Connection(host='127.0.0.1',
                            port=3301,
                            user='sampleuser',
                            password='123456')

# Insert data
tuples = [(1, 'Roxette', 1986),
          (2, 'Scorpions', 1965),
          (3, 'Ace of Base', 1987),
          (4, 'The Beatles', 1960)]
print("Inserted tuples:")
for tuple in tuples:
    response = conn.insert(space_name='bands', values=tuple)
    print(response[0])

# Select by primary key
response = conn.select(space_name='bands', key=1)
print('Tuple selected by the primary key value:', response[0])

# Select by secondary key
response = conn.select(space_name='bands', key='The Beatles', index='band')
print('Tuple selected by the secondary key value:', response[0])

# Update
response = conn.update(space_name='bands',
                       key=2,
                       op_list=[('=', 'band_name', 'Pink Floyd')])
print('Updated tuple:', response[0])

# Upsert
conn.upsert(space_name='bands',
            tuple_value=(5, 'The Rolling Stones', 1962),
            op_list=[('=', 'band_name', 'The Doors')])

# Replace
response = conn.replace(space_name='bands', values=(1, 'Queen', 1970))
print('Replaced tuple:', response[0])

# Delete
response = conn.delete(space_name='bands', key=5)
print('Deleted tuple:', response[0])

# Call
response = conn.call('get_bands_older_than', 1966)
print('Stored procedure result:', response[0])

# Close connection
conn.close()
print('Connection is closed')

Starting a client application

To run the resulting application, pass the script name to the python command:

$ python hello.py
Inserted tuples:
[1, 'Roxette', 1986]
[2, 'Scorpions', 1965]
[3, 'Ace of Base', 1987]
[4, 'The Beatles', 1960]
Tuple selected by the primary key value: [1, 'Roxette', 1986]
Tuple selected by the secondary key value: [4, 'The Beatles', 1960]
Updated tuple: [2, 'Pink Floyd', 1965]
Replaced tuple: [1, 'Queen', 1970]
Deleted tuple: [5, 'The Rolling Stones', 1962]
Stored procedure result: [[2, 'Pink Floyd', 1965], [4, 'The Beatles', 1960]]
Connection is closed

Community Python connectors

Last update: September 2023

There are also several community-driven Python connectors:

• asynctnt with asyncio support
• aiotarantool also with asyncio support, no active maintenance
• gtarantool with gevent support, no active maintenance

The table below contains a feature comparison for asynctnt and tarantool-python.