I need to insert rows into PG one of the fields is date and time with time stamp, this is the time of incident, so I can not use --> current_timestamp function of Postgres at the time of insertion, so how can I then insert the time and date which I collected before into pg row in the same format as it would have been created by current_timestamp at that point in time.
A timestamp does not have "a format".
The recommended way to deal with timestamps is to use a PreparedStatement where you just pass a placeholder in the SQL and pass a "real" object through the API of your programming language. As I don't know Python, I don't know if it supports PreparedStatements and how the syntax for that would be.
If you want to put a timestamp literal into your generated SQL, you will need to follow some formatting rules when specifying the value (a literal does have a format).
Ivan's method will work, although I'm not 100% sure if it depends on the configuration of the PostgreSQL server.
A configuration (and language) independent solution to specify a timestamp literal is the ANSI SQL standard:
INSERT INTO some_table
(ts_column)
VALUES
(TIMESTAMP '2011-05-16 15:36:38');
Yes, that's the keyword TIMESTAMP followed by a timestamp formatted in ISO style (the TIMESTAMP keyword defines that format)
The other solution would be to use the to_timestamp() function where you can specify the format of the input literal.
INSERT INTO some_table
(ts_column)
VALUES
(to_timestamp('16-05-2011 15:36:38', 'dd-mm-yyyy hh24:mi:ss'));