How to pass in string as f-string into another method?

Question

I'm planning on passing in multiple f-string based templates into another general method that iterates over databases and tables.

My code:

@staticmethod
def query1_template():
 query = '''
 SELECT
'{db}' as db_name,
'{tbl}' as tbl_name,
'{config[db][tbl]['definition']}' as definition
'''
return query

def build(self, query, config):
 etl = ''
 for i, db in enumerate(self.datasets):
  for j, tbl in enumerate(self.datasets.get(db)):
   if i > 0 or j > 0: 
    etl += 'UNION ALL'
   etl += query

Current output:

SELECT
'{db}' as db_name,
'{tbl}' as tbl_name
UNION ALL
SELECT ...

My expected output should be having the {db} and {tbl} values actually filled out.

I've tried etl += query.format(db, tbl) as well but keep getting a key error for db.

Is there a way for this logic to work?

Answer 1

In the query1_template() method:

query = '''
 SELECT
'{db}' as db_name,
'{tbl}' as tbl_name,
'{definition}' as definition
'''

In the build() method:

etl += query.format(db=db, tbl=tbl, definition=config[db][tbl]['definition']