Source code for airflow.providers.amazon.aws.transfers.sql_to_s3

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from collections import namedtuple
from enum import Enum
from tempfile import NamedTemporaryFile
from typing import TYPE_CHECKING, Iterable, Mapping, Optional, Sequence, Union

import numpy as np
import pandas as pd
from typing_extensions import Literal

from airflow.exceptions import AirflowException
from airflow.hooks.base import BaseHook
from airflow.models import BaseOperator
from airflow.providers.amazon.aws.hooks.s3 import S3Hook
from airflow.providers.common.sql.hooks.sql import DbApiHook

if TYPE_CHECKING:
    from airflow.utils.context import Context


[docs]FILE_FORMAT = Enum(
    "FILE_FORMAT",
    "CSV, JSON, PARQUET",
)

[docs]FileOptions = namedtuple('FileOptions', ['mode', 'suffix', 'function'])

[docs]FILE_OPTIONS_MAP = {
    FILE_FORMAT.CSV: FileOptions('r+', '.csv', 'to_csv'),
    FILE_FORMAT.JSON: FileOptions('r+', '.json', 'to_json'),
    FILE_FORMAT.PARQUET: FileOptions('rb+', '.parquet', 'to_parquet'),
}


[docs]class SqlToS3Operator(BaseOperator):
    """
    Saves data from a specific SQL query into a file in S3.

    .. seealso::
        For more information on how to use this operator, take a look at the guide:
        :ref:`howto/operator:SqlToS3Operator`

    :param query: the sql query to be executed. If you want to execute a file, place the absolute path of it,
        ending with .sql extension. (templated)
    :param s3_bucket: bucket where the data will be stored. (templated)
    :param s3_key: desired key for the file. It includes the name of the file. (templated)
    :param replace: whether or not to replace the file in S3 if it previously existed
    :param sql_conn_id: reference to a specific database.
    :param parameters: (optional) the parameters to render the SQL query with.
    :param aws_conn_id: reference to a specific S3 connection
    :param verify: Whether or not to verify SSL certificates for S3 connection.
        By default SSL certificates are verified.
        You can provide the following values:

        - ``False``: do not validate SSL certificates. SSL will still be used
                (unless use_ssl is False), but SSL certificates will not be verified.
        - ``path/to/cert/bundle.pem``: A filename of the CA cert bundle to uses.
                You can specify this argument if you want to use a different
                CA cert bundle than the one used by botocore.
    :param file_format: the destination file format, only string 'csv', 'json' or 'parquet' is accepted.
    :param pd_kwargs: arguments to include in DataFrame ``.to_parquet()``, ``.to_json()`` or ``.to_csv()``.
    """

[docs]    template_fields: Sequence[str] = (
        's3_bucket',
        's3_key',
        'query',
    )
[docs]    template_ext: Sequence[str] = ('.sql',)
[docs]    template_fields_renderers = {
        "query": "sql",
        "pd_kwargs": "json",
    }

    def __init__(
        self,
        *,
        query: str,
        s3_bucket: str,
        s3_key: str,
        sql_conn_id: str,
        parameters: Union[None, Mapping, Iterable] = None,
        replace: bool = False,
        aws_conn_id: str = 'aws_default',
        verify: Optional[Union[bool, str]] = None,
        file_format: Literal['csv', 'json', 'parquet'] = 'csv',
        pd_kwargs: Optional[dict] = None,
        **kwargs,
    ) -> None:
        super().__init__(**kwargs)
        self.query = query
        self.s3_bucket = s3_bucket
        self.s3_key = s3_key
        self.sql_conn_id = sql_conn_id
        self.aws_conn_id = aws_conn_id
        self.verify = verify
        self.replace = replace
        self.pd_kwargs = pd_kwargs or {}
        self.parameters = parameters

        if "path_or_buf" in self.pd_kwargs:
            raise AirflowException('The argument path_or_buf is not allowed, please remove it')

        self.file_format = getattr(FILE_FORMAT, file_format.upper(), None)

        if self.file_format is None:
            raise AirflowException(f"The argument file_format doesn't support {file_format} value.")

    @staticmethod
    def _fix_int_dtypes(df: pd.DataFrame) -> None:
        """Mutate DataFrame to set dtypes for int columns containing NaN values."""
        for col in df:
            if "float" in df[col].dtype.name and df[col].hasnans:
                # inspect values to determine if dtype of non-null values is int or float
                notna_series = df[col].dropna().values
                if np.equal(notna_series, notna_series.astype(int)).all():
                    # set to dtype that retains integers and supports NaNs
                    df[col] = np.where(df[col].isnull(), None, df[col])
                    df[col] = df[col].astype(pd.Int64Dtype())
                elif np.isclose(notna_series, notna_series.astype(int)).all():
                    # set to float dtype that retains floats and supports NaNs
                    df[col] = np.where(df[col].isnull(), None, df[col])
                    df[col] = df[col].astype(pd.Float64Dtype())

[docs]    def execute(self, context: 'Context') -> None:
        sql_hook = self._get_hook()
        s3_conn = S3Hook(aws_conn_id=self.aws_conn_id, verify=self.verify)
        data_df = sql_hook.get_pandas_df(sql=self.query, parameters=self.parameters)
        self.log.info("Data from SQL obtained")

        self._fix_int_dtypes(data_df)
        file_options = FILE_OPTIONS_MAP[self.file_format]

        with NamedTemporaryFile(mode=file_options.mode, suffix=file_options.suffix) as tmp_file:

            self.log.info("Writing data to temp file")
            getattr(data_df, file_options.function)(tmp_file.name, **self.pd_kwargs)

            self.log.info("Uploading data to S3")
            s3_conn.load_file(
                filename=tmp_file.name, key=self.s3_key, bucket_name=self.s3_bucket, replace=self.replace
            )

    def _get_hook(self) -> DbApiHook:
        self.log.debug("Get connection for %s", self.sql_conn_id)
        conn = BaseHook.get_connection(self.sql_conn_id)
        hook = conn.get_hook()
        if not callable(getattr(hook, 'get_pandas_df', None)):
            raise AirflowException(
                "This hook is not supported. The hook class must have get_pandas_df method."
            )
        return hook