Question

What function can I use to adapt values for suitable use in a COPY FROM statement? I tried this adapt function:

from psycopg2.extensions import adapt

However, it gives the wrong thing for datetimes (appends ::timestsamp to the string, postgres doesn’t like it) and string (wraps them in single quotes, e.g. empty string is ”, where it seems no quotes should be used).

Answer 1

You shouldn’t just use adapt with copy_from.

copy_from expects a format different than SQL quoting.

For strings, I’d suggest to write your own copy_adapt function, which should escape tabs with \t, CR with \r and LF with \n.

Values for timestamp / date columns should be formatted (with strftime?) like the string which you see when you SELECT now() in Postgres.

Tuple elements should be saparated by tabs, and whole tuple finished with newline.