Writing a convenient and decent-looking wrapper for working with transactions is a favorite pastime for many developers. Transactions must be able to start, finish and rollback properly, and they can also be nested. Python is a multifaceted language (or, as speechwriters say, “Multi-paradigm”), giving us innumerable ways of doing it.

As a foundation, I usually use Python DB API (namely, psycopg2 module). The API itself is rather low-level and is crying for improvement. What can be done?

Initially, let’s just make an ordinary decorator for opening and closing a transaction:
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