psycodict.base

The shared plumbing underneath every psycodict object.

PostgresBase is the common base of the database, table and statistics classes; it owns statement execution through _execute (logging, slow-query warnings, commit/rollback bookkeeping and reconnection) together with helpers for inspecting tables, indexes and constraints. The module also defines the layout of the meta_* tables – the column lists, types and creation statements shared by everything that reads or writes them – and the metadata format version (META_FORMAT) stamped into meta_format.

psycodict.base.jsonb_idx(cols, cols_type)

The positions in cols whose type is jsonb, as a tuple of indexes. Used to decide which values need json decoding when reading rows of the meta_* tables.

INPUT:

• cols – a list of column names

• cols_type – a dictionary mapping column names to their types

psycodict.base.export_format_line()

The marker line a new search-data export begins with, without a newline.

psycodict.base.export_format_version(line)

The export-format version a marker line declares.

INPUT:

• line – a line known to be a format marker rather than a row of column names.

OUTPUT:

The nonnegative integer version, or a ValueError if line is not exactly # psycodict-export-format: N. A signed or non-decimal version is malformed: psycodict has never written one, so a file carrying one was not written by any psycodict.

class psycodict.base.PostgresBase(loggername, db)

Bases: object

A base class for various objects that interact with Postgres.

Any class inheriting from this one must provide a connection to the postgres database, as well as a name used when creating a logger.