Question

psycopg2’s doc has an instruction on how to cast a specific type to a different type:

Psycopg converts decimal/numeric database types into Python Decimal objects. Can I have float instead?
You can register a customized adapter for PostgreSQL decimal type:

    DEC2FLOAT = psycopg2.extensions.new_type(
        psycopg2.extensions.DECIMAL.values,
        'DEC2FLOAT',
        lambda value, curs: float(value) if value is not None else None)
    psycopg2.extensions.register_type(DEC2FLOAT)

But my data will have a mixture of str, float, integer, decimal, date type, etc. How do i tell psycopg2 to cast any non string value to string? I don’t want to register a customized adapter everytime I encounter a new type because my query could change.
I hope I make the situation clear enough.
thanks in advance.

Answer 1

You could delete all the typecasters and receive everything in the postgres string representation:

import psycopg2

for k in psycopg2.extensions.string_types.keys():
    del psycopg2.extensions.string_types[k]

cnn = psycopg2.connect('')
cur = cnn.cursor()
cur.execute("select 1::int, now()::timestamp, 'hello'::text")
cur.fetchone()
('1', '2011-12-19 16:50:11.396855', 'hello')