Python 3.8导入模块和自定义模块的顺序

我对导入顺序和使用感到困惑。正如您在下面的代码中看到的那样，首先，我首先导入psycopg2。然后，我导入data_connect（依赖于psycopg2），所以有两个问题：（1）为什么解释器看不到我已经导入了psycopg2？（2）如何解决？谢谢！

错误信息：

File "C:\home\partscobra.com\wwwroot\data_connect.py" in data_connect:
db_conn = psycopg2.connect(...
NameError: name 'psycopg2' is not defined"

main.py：

import psycopg2
from data_connect import data_connect, data_cursor
#error here
[snip]

data_connect.py：

def data_connect():
    t_host = "blahblahblah"
    t_port = "5432"
    t_dbname = "inventory"
    t_user = "remote"
    t_pw = "blahblahblah"
    db_conn = psycopg2.connect(
        host=t_host,
        port=t_port,
        dbname=t_dbname,
        user=t_user,
        password=t_pw
        )
    db_conn.autocommit=True
    return db_conn

def data_cursor():
    db_conn = data_connect()
    db_cursor = db_conn.cursor()
    return db_cursor