New user questions

I'm starting to learn psycopg2 and have read the basic module usage doc. Two
questions on syntax:

1) I've seen a number of psycopg2 cursor execute examples where the select
or insert statement is enclosed in a pydoc pair of three double quotes. Most
examples in the basic module usage examples have a single pair of double
quotes enclosing the statement; the named variable examples are exceptions.
Is there a general rule when to use triple double quotes and when to use
single double quotes?

2) How do I write a cursor execute UPDATE statement where the columns and
values to be updated can be single or multiple and the values passed into
the method from the tkinter widgets? Are there examples from which I can
learn?

Regards,

Rich