pytd

pytd provides user-friendly interfaces to Treasure Data’s REST APIs, Presto query engine, and Plazma primary storage.

The seamless connection allows your Python code to efficiently read/write a large volume of data from/to Treasure Data. Eventually, pytd makes your day-to-day data analytics work more productive.

Installation

pip install pytd

Usage

• Documentation
• Sample usage on Google Colaboratory

Set your API key and endpoint to the environment variables, TD_API_KEY and TD_API_SERVER, respectively, and create a client instance:

import pytd

client = pytd.Client(database='sample_datasets')
# or, hard-code your API key, endpoint, and/or query engine:
# >>> pytd.Client(apikey='1/XXX', endpoint='https://api.treasuredata.com/', database='sample_datasets', default_engine='presto')

Query in Treasure Data

Issue Presto query and retrieve the result:

client.query('select symbol, count(1) as cnt from nasdaq group by 1 order by 1')
# {'columns': ['symbol', 'cnt'], 'data': [['AAIT', 590], ['AAL', 82], ['AAME', 9252], ..., ['ZUMZ', 2364]]}

In case of Hive:

client.query('select hivemall_version()', engine='hive')
# {'columns': ['_c0'], 'data': [['0.6.0-SNAPSHOT-201901-r01']]} (as of Feb, 2019)

It is also possible to explicitly initialize pytd.Client for Hive:

client_hive = pytd.Client(database='sample_datasets', default_engine='hive')
client_hive.query('select hivemall_version()')

Write data to Treasure Data

Data represented as pandas.DataFrame can be written to Treasure Data as follows:

import pandas as pd

df = pd.DataFrame(data={'col1': [1, 2], 'col2': [3, 10]})
client.load_table_from_dataframe(df, 'takuti.foo', writer='bulk_import', if_exists='overwrite')

For the writer option, pytd supports three different ways to ingest data to Treasure Data:

1. Bulk Import API: bulk_import (default)
   • Convert data into a CSV file and upload in the batch fashion.
2. Presto INSERT INTO query: insert_into
   • Insert every single row in DataFrame by issuing an INSERT INTO query through the Presto query engine.
   • Recommended only for a small volume of data.
3. td-spark: spark
   • Local customized Spark instance directly writes DataFrame to Treasure Data’s primary storage system.

Characteristics of each of these methods can be summarized as follows:

Enabling Spark Writer

Since td-spark gives special access to the main storage system via PySpark, follow the instructions below:

1. Contact [email protected] to activate the permission to your Treasure Data account. Note that the underlying component, Plazma Public API, limits its free tier at 100GB Read and 100TB Write.
2. Install pytd with [spark] option if you use the third option: pip install pytd[spark]

If you want to use existing td-spark JAR file, creating SparkWriter with td_spark_path option would be helpful.

from pytd.writer import SparkWriter

writer = SparkWriter(td_spark_path='/path/to/td-spark-assembly.jar')
client.load_table_from_dataframe(df, 'mydb.bar', writer=writer, if_exists='overwrite')

Comparison between pytd, td-client-python, and pandas-td

Treasure Data offers three different Python clients on GitHub, and the following list summarizes their characteristics.

1. td-client-python
   • Basic REST API wrapper.
   • Similar functionalities to td-client-{ruby, java, node, go}.
   • The capability is limited by what Treasure Data REST API can do.
2. pytd
   • Access to Plazma via td-spark as introduced above.
   • Efficient connection to Presto based on presto-python-client.
   • Multiple data ingestion methods and a variety of utility functions.
3. pandas-td (deprecated)
   • Old tool optimized for pandas and Jupyter Notebook.
   • pytd offers its compatible function set (see below for the detail).

An optimal choice of package depends on your specific use case, but common guidelines can be listed as follows:

• Use td-client-python if you want to execute basic CRUD operations from Python applications.
• Use pytd for (1) analytical purpose relying on pandas and Jupyter Notebook, and (2) achieving more efficient data access at ease.
• Do not use pandas-td. If you are using pandas-td, replace the code with pytd based on the following guidance as soon as possible.

How to replace pandas-td

pytd offers pandas-td-compatible functions that provide the same functionalities more efficiently. If you are still using pandas-td, we recommend you to switch to pytd as follows.

First, install the package from PyPI:

pip install pytd
# or, `pip install pytd[spark]` if you wish to use `to_td`

Next, make the following modifications on the import statements.

Before:

import pandas_td as td

In [1]: %%load_ext pandas_td.ipython

After:

import pytd.pandas_td as td

In [1]: %%load_ext pytd.pandas_td.ipython

Consequently, all pandas_td code should keep running correctly with pytd. Report an issue from here if you noticed any incompatible behaviors.