Snowflake with Pandas (dagster-snowflake-pandas)¶

This library provides an integration with the Snowflake data warehouse and Pandas data processing library.

To use this library, you should first ensure that you have an appropriate Snowflake user configured to access your data warehouse.

Related Guides:

• Using Dagster with Snowflake guide

dagster_snowflake_pandas.snowflake_pandas_io_manager IOManagerDefinition¶

Config Schema:

database (dagster.StringSource):

Name of the database to use.

account (dagster.StringSource):

Your Snowflake account name. For more details, see https://bit.ly/2FBL320.

user (dagster.StringSource):

User login name.

password (dagster.StringSource):

User password.

warehouse (dagster.StringSource, optional):

Name of the warehouse to use.

schema (dagster.StringSource, optional):

Name of the schema to use

role (dagster.StringSource, optional):

Name of the role to use

An IO manager definition that reads inputs from and writes pandas dataframes to Snowflake.

Returns:

IOManagerDefinition

Examples

from dagster_snowflake_pandas import snowflake_pandas_io_manager

@asset(
    key_prefix=["my_schema"]  # will be used as the schema in snowflake
)
def my_table() -> pd.DataFrame:  # the name of the asset will be the table name
    ...

@repository
def my_repo():
    return with_resources(
        [my_table],
        {"io_manager": snowflake_pandas_io_manager.configured({
            "database": "my_database",
            "account" : {"env": "SNOWFLAKE_ACCOUNT"}
            ...
        })}
    )

If you do not provide a schema, Dagster will determine a schema based on the assets and ops using the IO Manager. For assets, the schema will be determined from the asset key. For ops, the schema can be specified by including a “schema” entry in output metadata. If “schema” is not provided via config or on the asset/op, “public” will be used for the schema.

@op(
    out={"my_table": Out(metadata={"schema": "my_schema"})}
)
def make_my_table() -> pd.DataFrame:
    # the returned value will be stored at my_schema.my_table
    ...

To only use specific columns of a table as input to a downstream op or asset, add the metadata “columns” to the In or AssetIn.

@asset(
    ins={"my_table": AssetIn("my_table", metadata={"columns": ["a"]})}
)
def my_table_a(my_table: pd.DataFrame) -> pd.DataFrame:
    # my_table will just contain the data from column "a"
    ...

class dagster_snowflake_pandas.SnowflakePandasTypeHandler(*args, **kwds)[source]¶

Plugin for the Snowflake I/O Manager that can store and load Pandas DataFrames as Snowflake tables.

Examples:

from dagster_snowflake import build_snowflake_io_manager
from dagster_snowflake_pandas import SnowflakePandasTypeHandler

snowflake_io_manager = build_snowflake_io_manager([SnowflakePandasTypeHandler()])

@job(resource_defs={'io_manager': snowflake_io_manager})
def my_job():
    ...