我正在尝试使用dict构建一个sqlalchemy引擎，该字典具有从tkinter解析为其的变量 [英] I am trying to construct an sqlalchemy engine using a dict which has variables parsed to it from tkinter

问题描述

任何帮助将不胜感激.我有一个使用sqlalchemy的连接引擎，它可以完美连接.我想在用户在tkinter条目框中提供信息的地方使其动态化，然后将该信息解析为dict，然后由函数调用，然后从那里创建引擎.

Any help would be most appreciated. I have a connect engine using sqlalchemy, which connects perfectly. I would like to make it dynamic where a user provides the info in a tkinter Entry box and that information gets parsed into a dict which in turn gets called by a function and the engine is created from there.

我的工作引擎是:

engine =    sqlalchemy.create_engine('postgresql+pg8000://myuser:mypass@localhost/mydb')

我想要这样的东西

sqlalchemy.create_engine('postgresql+pg8000://DBUSER:DBPASS@DBHOST/DBNAME')

首先将变量由tkinter Entry提供，然后放入dict中，然后由连接函数读取.

where the variables are first supplied by tkinter Entry and placed into a dict, then read by the connection function.

我有以下内容

from sqlalchemy import create_engine
from sqlalchemy.engine import url

"""
These vars below are for testing. Ultimately they will be resolved
by a get() from tkinter which will take the values entered by a 
user into an Entry widget and place them into the dict below. 
The db_connect() func should build the url from the dict.
"""

DBNAME = 'mydb'
DBUSER = 'myuser'
DBPASS = 'password'
DBHOST ='localhost'
PNUM = '5432'
import json
import urllib.request as myurl

DATABASE = {
    'drivername': 'postgres+pg8000',
    'host': DBHOST,
    'port': PNUM,
    'username': DBUSER,
    'password': DBPASS,
    'database': DBNAME
}

def db_connect():
    create_engine(url(DATABASE))
"""This func should create the db engine connect


connect = sqlalchemy.create_engine(db_connect())

df = pd.read_sql("SELECT * FROM nc_data",con=connect)

我收到错误

db_connect 返回create_engine(url(DATABASE)) TypeError:模块"对象不可调用

db_connect return create_engine(url(DATABASE)) TypeError: 'module' object is not callable

推荐答案

使用关键字参数将其输入到sqlalchemy的url.URL()函数中

Feed it into sqlalchemy's url.URL() function by using keyword arguments

create_engine(url.URL(**DATABASE))

请注意**，正确的方法是url.URL()，而不仅是url，按照

Notice the ** and the correct method is url.URL(), not just url as per http://docs.sqlalchemy.org/en/rel_1_0/core/engines.html#sqlalchemy.engine.url.URL

有关**功能的参考: https://docs.python.org/2/tutorial/controlflow.html#unpacking-argument-lists

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