AttributeError: 'NoneType' object has no attribute 'cursor' – Getting this error when trying to use pd.read_sql() with flask-sqlalchemy query
Question:
I have a flask-sqlalchemy query. I know that the below flask-sqlalchemy query code is valid because I am able to populate data on another page in an html table with the ‘eintest’ variable.
ticker = 'msft'
eintest = db.session.query(company).filter(company.instance==ticker)
All I am trying to do is convert that flask-sqlalchemy code above into a pandas data frame, as I am trying to do below.
df = pd.read_sql(eintest.statement, db.session.bind)
When I run my flask app, I get the error, "AttributeError: ‘NoneType’ object has no attribute ‘cursor’". Does anyone know why this is? I’ve been trying many variations of that one line to read sql into a pandas dataframe but no luck yet.
Answers:
Arguments for pandas read_sql is a sql statement and a connection. You are passing a statement and a session. Here’s what you’ll need to change to get it to work:
# Load to a pandas dataframe
df = pd.read_sql(eintest.statement, db.get_engine())
I have a flask-sqlalchemy query. I know that the below flask-sqlalchemy query code is valid because I am able to populate data on another page in an html table with the ‘eintest’ variable.
ticker = 'msft'
eintest = db.session.query(company).filter(company.instance==ticker)
All I am trying to do is convert that flask-sqlalchemy code above into a pandas data frame, as I am trying to do below.
df = pd.read_sql(eintest.statement, db.session.bind)
When I run my flask app, I get the error, "AttributeError: ‘NoneType’ object has no attribute ‘cursor’". Does anyone know why this is? I’ve been trying many variations of that one line to read sql into a pandas dataframe but no luck yet.
Arguments for pandas read_sql is a sql statement and a connection. You are passing a statement and a session. Here’s what you’ll need to change to get it to work:
# Load to a pandas dataframe
df = pd.read_sql(eintest.statement, db.get_engine())