Python cannot connect to MySQL if declare in a class

Question

I'm newbie in Python. I'm trying to use Python to connect MySQL Server. I wrote like guides from MySQL official page, it was OK. But, when I create a connector class, it raised the error "MySQL Connection not available"

Here is my class

import mysql.connector
from mysql.connector import errorcode

##  BEGIN MySQL Connector Class
class MySQLConnector :
    configs = {
        "user":"root",
        "password":"",
        "host":"127.0.0.1",
        "database":"python_db",
        "raise_on_warnings": True
    }
    cursor = None
    connection = None

    ##  BEGIN Constructor
    def __init__(self, configs = {}) :
        if(any(configs)!=False) :
            self.configs = configs
    ##  END Constructor

    ##  BEGIN Open
    def open(self) :
        try:
            self.connection = mysql.connector.connect(self.configs)
        except mysql.connector.Error as err:
            if err.errno == errorcode.ER_ACCESS_DENIED_ERROR:
                print("Something is wrong with your user name or password")
            elif err.errno == errorcode.ER_BAD_DB_ERROR:
                print("Database does not exists")
            else:
                print(err)
        finally:
            self.connection.close()
        return self.connection
    ##  END Open

    ##  BEGIN close connection
    def close(self) :
        self.cursor.close()
        self.connection.close()
    ##  END close connection

    ##  BEGIN execute
    def execute(self, query) :
        if(self.connection == None) :
            print("Connection is None")
            return
        self.cursor = self.connection.cursor()
        if(self.cursor!=None) :
            self.cursor.execute(query)
        else:
            print("Cursor is 'None'")
    ##  END execute



##  END MySQL Connector Class

##  BEGIN RUN
objConnect = MySQLConnector()
objConnect.open()
objConnect.execute("SELECT * FROM User")

Please show me the way to solution and explained me why my code has error.

Thanks!

EDITED

Finally, mata and alecxe help me to solve this problem, I don't know which solution to be choosen. I summary here for someone has mistake like me: 1. Remove the finally statement. 2. Using ** in self.connection = mysql.connector.connect(**self.configs)

## BEGIN MySQL Connector Class ... ## END MySQL Connector Class - this makes any python programmer's eyes bleed. — mata
– mata, Commented Jul 18, 2013 at 11:20
if(any(configs)!=False) seems wrong to me, as the condition nearly always is true. What did you mean to accomplish? — glglgl
– glglgl, Commented Jul 18, 2013 at 12:14
@glglgl you'll find it difference when using this objConnect = MySQLConnect(other_configs) — Gia Duong Duc Minh
– Gia Duong Duc Minh, Commented Jul 19, 2013 at 2:11
@GiaDuongDucMinh Yes, but the way you write it seems suspicious to me. Did you just mean if configs: (testing if configs is non-empty)? Or if any(configs): (testing if it has at least one non-empty key)? What you do is testing if it has a value which evaluates to a tru-ish key (!) and compare that with False, which could never be the way except if it only has falsey values or is empty. So it is the same as if any(configs):, but very more complicated and very harder to understand. — glglgl
– glglgl, Commented Jul 19, 2013 at 5:07

mata · Accepted Answer · 2013-07-18 11:28:06Z

3

Even if you correct the error alecxe pointed out, your code still won't work.

The finally block ensures that each connection is closed before it is returned, no matter wheather there was an exception or not, so the open method only returns closed connections.

answered Jul 18, 2013 at 11:28

mata

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1 Comment

Gia Duong Duc Minh Over a year ago

Thank you! Your solution and alecxe's are fit for my problem.

alecxe · Accepted Answer · 2013-07-18 11:11:33Z

3

You are passing a dictionary object self.configs into mysql.connector.connect, though, according to docs, you should pass to it user, password and other arguments. Looks like you need to unpack configs:

self.connection = mysql.connector.connect(**self.configs)

Hope this is it.

answered Jul 18, 2013 at 11:11

alecxe

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1 Comment

Gia Duong Duc Minh Over a year ago

Thank you! Your solution and mata's are fit for my problem.

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