awswrangler.s3.to_csv

awswrangler.s3.to_csv(df: pandas.core.frame.DataFrame, path: str, sep: str = ',', index: bool = True, columns: Optional[List[str]] = None, use_threads: bool = True, boto3_session: Optional[boto3.session.Session] = None, s3_additional_kwargs: Optional[Dict[str, str]] = None, sanitize_columns: bool = False, dataset: bool = False, partition_cols: Optional[List[str]] = None, mode: Optional[str] = None, catalog_versioning: bool = False, database: Optional[str] = None, table: Optional[str] = None, dtype: Optional[Dict[str, str]] = None, description: Optional[str] = None, parameters: Optional[Dict[str, str]] = None, columns_comments: Optional[Dict[str, str]] = None, regular_partitions: bool = True, projection_enabled: bool = False, projection_types: Optional[Dict[str, str]] = None, projection_ranges: Optional[Dict[str, str]] = None, projection_values: Optional[Dict[str, str]] = None, projection_intervals: Optional[Dict[str, str]] = None, projection_digits: Optional[Dict[str, str]] = None, **pandas_kwargs) → Dict[str, Union[List[str], Dict[str, List[str]]]]

Write CSV file or dataset on Amazon S3.

The concept of Dataset goes beyond the simple idea of files and enable more complex features like partitioning, casting and catalog integration (Amazon Athena/AWS Glue Catalog).

Note

If dataset=True The table name and all column names will be automatically sanitized using wr.catalog.sanitize_table_name and wr.catalog.sanitize_column_name. Please, pass sanitize_columns=True to force the same behaviour for dataset=False.

Note

On append mode, the parameters will be upsert on an existing table.

Note

In case of use_threads=True the number of threads that will be spawned will be get from os.cpu_count().

Parameters
  • df (pandas.DataFrame) – Pandas DataFrame https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.html

  • path (str) – Amazon S3 path (e.g. s3://bucket/filename.csv).

  • sep (str) – String of length 1. Field delimiter for the output file.

  • index (bool) – Write row names (index).

  • columns (List[str], optional) – Columns to write.

  • use_threads (bool) – True to enable concurrent requests, False to disable multiple threads. If enabled os.cpu_count() will be used as the max number of threads.

  • boto3_session (boto3.Session(), optional) – Boto3 Session. The default boto3 Session will be used if boto3_session receive None.

  • s3_additional_kwargs – Forward to s3fs, useful for server side encryption https://s3fs.readthedocs.io/en/latest/#serverside-encryption

  • sanitize_columns (bool) – True to sanitize columns names or False to keep it as is. True value is forced if dataset=True.

  • dataset (bool) – If True store a parquet dataset instead of a single file. If True, enable all follow arguments: partition_cols, mode, database, table, description, parameters, columns_comments, .

  • partition_cols (List[str], optional) – List of column names that will be used to create partitions. Only takes effect if dataset=True.

  • mode (str, optional) – append (Default), overwrite, overwrite_partitions. Only takes effect if dataset=True.

  • catalog_versioning (bool) – If True and mode=”overwrite”, creates an archived version of the table catalog before updating it.

  • database (str, optional) – Glue/Athena catalog: Database name.

  • table (str, optional) – Glue/Athena catalog: Table name.

  • dtype (Dict[str, str], optional) – Dictionary of columns names and Athena/Glue types to be casted. Useful when you have columns with undetermined or mixed data types. (e.g. {‘col name’: ‘bigint’, ‘col2 name’: ‘int’})

  • description (str, optional) – Glue/Athena catalog: Table description

  • parameters (Dict[str, str], optional) – Glue/Athena catalog: Key/value pairs to tag the table.

  • columns_comments (Dict[str, str], optional) – Glue/Athena catalog: Columns names and the related comments (e.g. {‘col0’: ‘Column 0.’, ‘col1’: ‘Column 1.’, ‘col2’: ‘Partition.’}).

  • regular_partitions (bool) – Create regular partitions (Non projected partitions) on Glue Catalog. Disable when you will work only with Partition Projection. Keep enabled even when working with projections is useful to keep Redshift Spectrum working with the regular partitions.

  • projection_enabled (bool) – Enable Partition Projection on Athena (https://docs.aws.amazon.com/athena/latest/ug/partition-projection.html)

  • projection_types (Optional[Dict[str, str]]) – Dictionary of partitions names and Athena projections types. Valid types: “enum”, “integer”, “date”, “injected” https://docs.aws.amazon.com/athena/latest/ug/partition-projection-supported-types.html (e.g. {‘col_name’: ‘enum’, ‘col2_name’: ‘integer’})

  • projection_ranges (Optional[Dict[str, str]]) – Dictionary of partitions names and Athena projections ranges. https://docs.aws.amazon.com/athena/latest/ug/partition-projection-supported-types.html (e.g. {‘col_name’: ‘0,10’, ‘col2_name’: ‘-1,8675309’})

  • projection_values (Optional[Dict[str, str]]) – Dictionary of partitions names and Athena projections values. https://docs.aws.amazon.com/athena/latest/ug/partition-projection-supported-types.html (e.g. {‘col_name’: ‘A,B,Unknown’, ‘col2_name’: ‘foo,boo,bar’})

  • projection_intervals (Optional[Dict[str, str]]) – Dictionary of partitions names and Athena projections intervals. https://docs.aws.amazon.com/athena/latest/ug/partition-projection-supported-types.html (e.g. {‘col_name’: ‘1’, ‘col2_name’: ‘5’})

  • projection_digits (Optional[Dict[str, str]]) – Dictionary of partitions names and Athena projections digits. https://docs.aws.amazon.com/athena/latest/ug/partition-projection-supported-types.html (e.g. {‘col_name’: ‘1’, ‘col2_name’: ‘2’})

  • pandas_kwargs – keyword arguments forwarded to pandas.DataFrame.to_csv() https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.to_csv.html

Returns

None.

Return type

None

Examples

Writing single file

>>> import awswrangler as wr
>>> import pandas as pd
>>> wr.s3.to_csv(
...     df=pd.DataFrame({'col': [1, 2, 3]}),
...     path='s3://bucket/prefix/my_file.csv',
... )
{
    'paths': ['s3://bucket/prefix/my_file.csv'],
    'partitions_values': {}
}

Writing single file encrypted with a KMS key

>>> import awswrangler as wr
>>> import pandas as pd
>>> wr.s3.to_csv(
...     df=pd.DataFrame({'col': [1, 2, 3]}),
...     path='s3://bucket/prefix/my_file.csv',
...     s3_additional_kwargs={
...         'ServerSideEncryption': 'aws:kms',
...         'SSEKMSKeyId': 'YOUR_KMY_KEY_ARN'
...     }
... )
{
    'paths': ['s3://bucket/prefix/my_file.csv'],
    'partitions_values': {}
}

Writing partitioned dataset

>>> import awswrangler as wr
>>> import pandas as pd
>>> wr.s3.to_csv(
...     df=pd.DataFrame({
...         'col': [1, 2, 3],
...         'col2': ['A', 'A', 'B']
...     }),
...     path='s3://bucket/prefix',
...     dataset=True,
...     partition_cols=['col2']
... )
{
    'paths': ['s3://.../col2=A/x.csv', 's3://.../col2=B/y.csv'],
    'partitions_values: {
        's3://.../col2=A/': ['A'],
        's3://.../col2=B/': ['B']
    }
}

Writing dataset to S3 with metadata on Athena/Glue Catalog.

>>> import awswrangler as wr
>>> import pandas as pd
>>> wr.s3.to_csv(
...     df=pd.DataFrame({
...         'col': [1, 2, 3],
...         'col2': ['A', 'A', 'B']
...     }),
...     path='s3://bucket/prefix',
...     dataset=True,
...     partition_cols=['col2'],
...     database='default',  # Athena/Glue database
...     table='my_table'  # Athena/Glue table
... )
{
    'paths': ['s3://.../col2=A/x.csv', 's3://.../col2=B/y.csv'],
    'partitions_values: {
        's3://.../col2=A/': ['A'],
        's3://.../col2=B/': ['B']
    }
}

Writing dataset casting empty column data type

>>> import awswrangler as wr
>>> import pandas as pd
>>> wr.s3.to_csv(
...     df=pd.DataFrame({
...         'col': [1, 2, 3],
...         'col2': ['A', 'A', 'B'],
...         'col3': [None, None, None]
...     }),
...     path='s3://bucket/prefix',
...     dataset=True,
...     database='default',  # Athena/Glue database
...     table='my_table'  # Athena/Glue table
...     dtype={'col3': 'date'}
... )
{
    'paths': ['s3://.../x.csv'],
    'partitions_values: {}
}