Question

I’m using python 2.7
I’m writing some query in python

q = '''
select * from users where user_name = %(user_name)s and  user_email = %(user_email)s
'''

I want to format the string in two step
something like :

q2 = q % {'user_name':'david'}
q3 = q2 % {'user_email':'[e-mail]'}

The example i wrote is not working. python throws KeyError
is there any other option to perform those tasks?

Answer 1

Use a proper database API.

That said, if you know which keys will be omitted in the first pass, you can do:

>>> "%(a)s and %%(b)s" % {'a': 1}
'1 and %(b)s'
>>> _ % {'b': 2}
'1 and 2'