formating query with empty parameter

[Peter Otten]

Pet wrote:

> > someone wrote:
> > > Hello!
> >
> > > if one of parameter in values is empty, I'm getting
> > > TypeError: not enough arguments for format string
> >
> > > But how to handle such situation? It is ok for DB, that some of values
> > > are empty.
> >
> > > def __insert(self, data):
> > >         query = """
> > >             BEGIN;
> > >                 INSERT INTO table
> > >                     (a,  b,  c,  d,  e,  f,  g)
> > >                     VALUES
> > >                     (%s, %s, %s, %s, %s, %s, %s);
> > >             COMMIT;
> > >             """
> > >         values = [
> > >             data['a'],
> > >             data['b'],
> > >             data['c'],
> > >             data['d'],
> > >             data['e'],
> > >             data['f'],
> > >             data['g']
> > >             ]
> > >         self.db.execute(query, *values)
> >
> > You need to pass
> >
> > None
> 
> Hi,
> 
> thanks for reply.
> Unfortunately, it doesn't work. Still getting TypeError: not enough
> arguments for format string
> 

The code you posted doesn't match that error message. You have to invoke 
cursor.execute() as 

cursor.execute(query, values) # correct

, not 

cursor.execute(query, *values) # wrong

or

cursor.execute(query % values) # wrong

The length of values must match the number of "%s" occurences in the sql 
query, but as Diez indicated you may pass None for every field that allows a 
NULL value in the table.

Peter