Hi all, I am unsure how to solve: I use adler32/crc32 to generate integer values from data for setting up an advisory lock in PostgreSQL.
The PG function pg_try_advisory_lock() https://www.postgresql.org/docs/12/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS takes two PG ints which are defined as: integer 4 bytes typical choice for integer -2147483648 to +2147483647 Now, in Py > 2.5 zlib.adler32/crc32 will return suitable integers. However, in Py3 the return range has been changed to The return value is unsigned and in the range [0, 2**32-1] regardless of platform. which will overflow the PostgreSQL function. Is there a way to convert/modify/shift the py3 value such that it shows the same representation as the py2 value ? What I am looking for is: v2 = py2.zlib.adler32(data) v3 = some_magic(py3.zlib.adler32(data)) if v2 == v3: print('same') I am sure there's something obvious with struct/<</& and such like which I am overlooking. Note that I can't simply do v2 = py2.zlib.adler32(data) & 0xffffffff because that can overflow the PostgreSQL integer. I think I need the reverse, in a sense, but I am too dense, ATM. Thanks for any help, Karsten -- https://mail.python.org/mailman/listinfo/python-list
