1、如果本機沒有裝Oracle資料庫，需要裝一個Instant Client

下載後解壓，然後把資料夾路徑新增至系統變數path。

新建文字文件 輸入：

orcl =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = sys)
    )
  )

2、將解壓的資料夾（比如instantclient_11_2）中的 

3、用pip 安裝 cx_Oracle

pip install cx_Oracle。不成功的話下載whl本地安裝。

4、python語句

import cx_Oracle

conn=cx_Oracle.connect('user','password', '127.0.0.1:1521/database') #這步不報錯就是連上啦
print('連線成功!')

cursor = conn.cursor()

sql="""
    select count(1) from table_1 

    """

cursor.execute(sql)
alldata = cursor.fetchall()  

cursor.close()
conn.close()