CODEWITHSUNDEEP
python
Jake McLaren
Jake McLaren

Reputation: 13

Python class attribute cannot be called within object scope

import pyodbc

class Database(object):

    def connect(self):
        connection = pyodbc.connect("""DRIVER={SQL Server};
                                       SERVER=XX\SQLEXPRESS;
                                       DATABASE=ACCOUNT_DBF;
                                       UID=sa;PWD=XXX""")
        cursor = connection.cursor()

    def check_account(self, usr):
        cursor.execute("SELECT * FROM ACCOUNT_TBL WHERE account = ?", usr)
        row = cursor.fetchone()

        print(row[0])

database = Database()
database.check_account("developer")

So, as you can see I am trying to call the "check_account" function with the parameter of "developer". But whenever I execute/build it, it gives me an error of

"NameError: name cursor not defined"

I am curious and new to python on how to actually do it. I've been searching around the web but I cannot find a specific answer for my problem.

*I am using the latest python btw(3.6.1).

Upvotes: 0

Views: 546

Answers (2)

nick
nick

Reputation: 853

Try:

class Database(object):

def connect(self):
    connection = pyodbc.connect("""DRIVER={SQL Server};
                                   SERVER=XX\SQLEXPRESS;
                                   DATABASE=ACCOUNT_DBF;
                                   UID=sa;PWD=XXX""")
    self.cursor = connection.cursor()

In your code, cursoris variable which below to method, only self.cursor can store cursor to class, and then other methods can use.

Upvotes: 0

Diego Navarro
Diego Navarro

Reputation: 9704

The NameError exception is triggered because in the check_account method you can not see local variables defined in connect method.

You need to set instance attributes "inside" self, since you can access self from all methods (it is the instance itself).

def connect(self):
    self.connection = pyodbc.connect("""DRIVER={SQL Server};
                                   SERVER=XX\SQLEXPRESS;
                                   DATABASE=ACCOUNT_DBF;
                                   UID=sa;PWD=XXX""")
    self.cursor = connection.cursor()

def check_account(self, usr):
    self.cursor.execute("SELECT * FROM ACCOUNT_TBL WHERE account = ?", usr)
    row = self.cursor.fetchone()

    print(row[0])

Upvotes: 2

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