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Connection not defined Error in the program

1 New Member
Dear All,
I have a problem while data logging in a single table in SQL DB. We are not able to do it. When we are running the python code in raspberry pi we are getting the following error msg.

Expand|Select|Wrap|Line Numbers
  1. import serial
  2. import time
  3. import MySQLdb as mdb
  5. arduino = serial.Serial("/dev/ttyACM0")
  6. arduino.baudrate=9600
  8. data = arduino.readline()
  9. time.sleep(1)
  10. data = arduino.readline()
  11. pieces = data.split("\t")
  13. temperature = pieces[0]
  14. humidity = pieces[1]
  16. con = mdb.connect('localhost', 'root', '12345678', 'testdb');
  18. with con:
  20.     cursor = connection.cursor(prepared=True)
  21.     sql_insert_query = """ INSERT INTO TempDB (temperature, humidity) VALUES (?,?)"""
  23.     insert_tuple = (temperature, humidity)
  24.     cursor.execute(sql_insert_query, insert_tuple)
  25.     connection.commit()
Error Message

Traceback (most recent call last):
File "./insertDB.py", line 20, in <module>
cursor = connection.curs or(prepared=Tru e)
NameError: name 'connection' is not defined
Jun 23 '20 #1
4 21990
9,065 Recognized Expert Moderator Expert
I'm not a Python expert but it looks to me like you added the with con: and forget to remove the connection. at lines 20 and 25.
Jun 23 '20 #2
83 New Member

You use con variable to store connection string and and use connection variable. so,use con instead of connection.
Jun 24 '20 #3
1 New Member
I got same error when tried to connect to DB wich was not yet created
Aug 24 '22 #4
1 New Member
When we try to access a variable or function that is not defined or before it is defined, Python throws the error "NameError: name is not defined." Make sure the variable's name is spelled correctly and access it after it has been defined to fix the issue. Here is an illustration of the fallacy in action. When a variable, function, or module is used in Python but either doesn't exist or wasn't used properly, a NameError is raised. Common errors that lead to this error include the following: using a name for a variable or function that hasn't yet been declared.
Sep 2 '22 #5

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