Modin Configuration Settings - Modin

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Modin Configuration Settings """"""""""""""""""""""""""""

To adjust Modin's default behavior, you can set the value of Modin configs by setting an environment variable or by using the modin.config API. To list all available configs in Modin, please run python -m modin.config to print all Modin configs with descriptions.

Public API ''''''''''

Potentially, the source of configs can be any, but for now only environment variables are implemented. Any environment variable originate from :class:~modin.config.envvars.EnvironmentVariable, which contains most of the config API implementation.

.. autoclass:: modin.config.envvars.EnvironmentVariable :members: get, put, get_help, get_value_source, once, subscribe

Modin Configs List ''''''''''''''''''

.. csv-table:: :file: configs_help.csv :header-rows: 1

Usage Guide '''''''''''

See example of interaction with Modin configs below, as it can be seen config value can be set either by setting the environment variable or by using config API.

.. code-block:: python

import os

# Setting `MODIN_ENGINE` environment variable.
# Also can be set outside the script.
os.environ["MODIN_ENGINE"] = "Dask"

import modin.config
import modin.pandas as pd

# Checking initially set `Engine` config,
# which corresponds to `MODIN_ENGINE` environment
# variable
print(modin.config.Engine.get()) # prints 'Dask'

# Checking default value of `NPartitions`
print(modin.config.NPartitions.get()) # prints '8'

# Changing value of `NPartitions`
modin.config.NPartitions.put(16)
print(modin.config.NPartitions.get()) # prints '16'

One can also use config variables with a context manager in order to use some config only for a certain part of the code:

.. code-block:: python

import modin.config as cfg

# Default value for this config is 'False'
print(cfg.RangePartitioning.get()) # False

# Set the config to 'True' inside of the context-manager
with cfg.context(RangePartitioning=True):
    print(cfg.RangePartitioning.get()) # True
    df.merge(...) # will use range-partitioning impl

# Once the context is over, the config gets back to its previous value
print(cfg.RangePartitioning.get()) # False

# You can also set multiple config at once when you pass a dictionary to 'cfg.context'
print(cfg.AsyncReadMode.get()) # False

with cfg.context(RangePartitioning=True, AsyncReadMode=True):
    print(cfg.RangePartitioning.get()) # True
    print(cfg.AsyncReadMode.get()) # True
print(cfg.RangePartitioning.get()) # False
print(cfg.AsyncReadMode.get()) # False