python - 如何将 Select * Postgres/Redshift 查询结果放入字典(列/值)

Question

我正在尝试使用列及其值将 postgres/redshift 查询的结果收集到字典中。

因此，如果我的 select * from ___ 语句的结果是:

字段1 |字段2 |字段3

值1 |值2 |值3

如何将结果放入字典中: field1:value1, field2,value2 等......

这是我的 Airflow 脚本:

#Import Modules

from datetime import datetime, timedelta
from airflow import DAG
from paramiko.config import SSH_PORT
from airflow.hooks.base_hook import BaseHook
from airflow.models import Variable
from airflow.operators.python_operator import PythonOperator
from airflow.hooks.postgres_hook import PostgresHook
from sshtunnel import SSHTunnelForwarder, create_logger
from io import StringIO
import logging
from distutils.util import execute
from contextlib import closing
import paramiko
import MySQLdb as sql
from contextlib import closing
import psycopg2
import psycopg2.extensions
from psycopg2.extras import RealDictCursor
import psycopg2.extras
import operator
import itertools
from query_tools import fetch, execute




def get_etl():
    pg_hook = PostgresHook(postgre_conn_id="postgres_default", schema='schema1')
    connection = pg_hook.get_conn()
    col_query = "select * from schema.table"
    cursor = connection.cursor()
    cursor.execute(col_query)
    ff = cursor.fetchall()
    connection.commit()
    connection.close()


# Identify Deafult Arguments

default_args = {
    'owner': 'm',
    'depends_on_past': False,
    'start_date': datetime(2019,12,15),
    'email': ['<a href="https://stackoverflow.com/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="f79a96b796989bd994989a" rel="noreferrer noopener nofollow">[email protected]</a>'],
    'email_on_failure': False,
    'email_on_retry': False,
    'retries': 1,
    'retry_delay': timedelta(minutes=1)
}


#Instantiate DAG instance

with DAG('try_me', description ='This ist by Maliva ', default_args = default_args, schedule_interval ='@hourly', catchup = False) as dag:
    t1 = PythonOperator(task_id ='new_one', python_callable = get_etl )

运行此脚本时，它会输出结果，但只输出记录:value1、value2、value3。

对于获取与值关联的列名有什么想法或建议吗？

Answer 1

您可以使用 itertools 来实现:

import itertools

pg_hook = PostgresHook(postgre_conn_id="postgres_default", schema='schema1')
connection = pg_hook.get_conn()
col_query = "select * from schema.table"
cursor = connection.cursor()
cursor.execute(col_query)
#fetchall to dictonary
desc = cursor.description
column_names = [col[0] for col in desc]
data = [dict(zip(column_names, row)) for row in cursor.fetchall()]
print(data)

#ff = cursor.fetchall()
connection.commit()
connection.close()