Variable argument list for IN clause

Hello,

I have an SQL with an IN clause.

If the number of params are fixed there no problem,

 >>> c = con.cursor()
 >>> c.execute("select 1 in (%s, %s, %s) ", (1,2,3))
 >>> c.fetchall()
[(True,)]
 >>>


The problem is if i don't know the number of params.

I try to calculate it at run time an replace the marker:

 >>> params = (1,2,3)
 >>> SQL = "select 1 in (%s)"
 >>> # count params and replace
 >>> SQL = SQL % ", ".join(["%s" for p in params])
 >>>
 >>> c.execute(SQL, params)
 >>> c.fetchall()
[(True,)]

But no work on more complex sql with another params out the IN clause.

How can avoid it? Is there any simple way?

Thanks,
-- 
*****************************************
Oswaldo Hernández
oswaldo (@) soft-com (.) es
*****************************************
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