Source code for airflow.contrib.operators.postgres_to_gcs_operator

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"""
PostgreSQL to GCS operator.
"""

import datetime
from decimal import Decimal
import time

import sys

from airflow.hooks.postgres_hook import PostgresHook
from airflow.utils.decorators import apply_defaults
from airflow.contrib.operators.sql_to_gcs import BaseSQLToGoogleCloudStorageOperator

[docs]PY3 = sys.version_info[0] == 3



[docs]class PostgresToGoogleCloudStorageOperator(BaseSQLToGoogleCloudStorageOperator):
    """
    Copy data from Postgres to Google Cloud Storage in JSON or CSV format.

    :param postgres_conn_id: Reference to a specific Postgres hook.
    :type postgres_conn_id: str
    """
[docs]    ui_color = '#a0e08c'

[docs]    type_map = {
        1114: 'TIMESTAMP',
        1184: 'TIMESTAMP',
        1082: 'TIMESTAMP',
        1083: 'TIMESTAMP',
        1005: 'INTEGER',
        1007: 'INTEGER',
        1016: 'INTEGER',
        20: 'INTEGER',
        21: 'INTEGER',
        23: 'INTEGER',
        16: 'BOOLEAN',
        700: 'FLOAT',
        701: 'FLOAT',
        1700: 'FLOAT',
    }

    @apply_defaults
    def __init__(self,
                 postgres_conn_id='postgres_default',
                 *args,
                 **kwargs):
        super(PostgresToGoogleCloudStorageOperator, self).__init__(*args, **kwargs)
        self.postgres_conn_id = postgres_conn_id

[docs]    def query(self):
        """
        Queries Postgres and returns a cursor to the results.
        """
        hook = PostgresHook(postgres_conn_id=self.postgres_conn_id)
        conn = hook.get_conn()
        cursor = conn.cursor()
        cursor.execute(self.sql, self.parameters)
        return cursor

[docs]    def field_to_bigquery(self, field):
        return {
            'name': field[0],
            'type': self.type_map.get(field[1], "STRING"),
            'mode': 'REPEATED' if field[1] in (1009, 1005, 1007,
                                               1016) else 'NULLABLE'
        }

[docs]    def convert_type(self, value, schema_type):
        """
        Takes a value from Postgres, and converts it to a value that's safe for
        JSON/Google Cloud Storage/BigQuery. Dates are converted to UTC seconds.
        Decimals are converted to floats. Times are converted to seconds.
        """
        if isinstance(value, (datetime.datetime, datetime.date)):
            return time.mktime(value.timetuple())
        if isinstance(value, datetime.time):
            formated_time = time.strptime(str(value), "%H:%M:%S")
            return int(datetime.timedelta(
                hours=formated_time.tm_hour,
                minutes=formated_time.tm_min,
                seconds=formated_time.tm_sec).total_seconds())
        if isinstance(value, Decimal):
            return float(value)
        return value