Database connections

MySQL database connection.

Requires: MySQLdb python module

Usage: db.MySQLdb(host='127.0.0.1',port=3306,dbname='sagator',
                  dbuser='sagator',dbpasswd='xxxxxx')

Parameters:
      host            - database server hostname or unix socket path
      port            - tcp socket port for database server
      dbname          - database name
      dbuser          - authorization username
      dbpasswd        - authorization password

Database creation script:     scripts/db/mysql.sh

Concrete implementation of SourceLoader using the file system.

The specification for a module, used for loading.

A module's spec is the source for information about the module.  For
data associated with the module, including source, use the spec's
loader.

`name` is the absolute name of the module.  `loader` is the loader
to use when loading the module.  `parent` is the name of the
package the module is in.  The parent is derived from the name.

`is_package` determines if the module is considered a package or
not.  On modules this is reflected by the `__path__` attribute.

`origin` is the specific location used by the loader from which to
load the module, if that information is available.  When filename is
set, origin will match.

`has_location` indicates that a spec's "origin" reflects a location.
When this is True, `__file__` attribute of the module is set.

`cached` is the location of the cached bytecode file, if any.  It
corresponds to the `__cached__` attribute.

`submodule_search_locations` is the sequence of path entries to
search when importing submodules.  If set, is_package should be
True--and False otherwise.

Packages are simply modules that (may) have submodules.  If a spec
has a non-None value in `submodule_search_locations`, the import
system will consider modules loaded from the spec as packages.

Only finders (see importlib.abc.MetaPathFinder and
importlib.abc.PathEntryFinder) should modify ModuleSpec instances.

PostgreSQL support via pg python module.

Requires: pg python module

Usage: db.pg(host='127.0.0.1',port=5432,dbname='sagator',
             dbuser='sagator',dbpasswd='xxxxxx')

Parameters:
      host            - database server hostname
      port            - tcp socket port for database server
      dbname          - database name
      dbuser          - authorization username
      dbpasswd        - authorization password

Database creation script:     scripts/db/pgsql.sh

PostgreSQL support via pgdb python module. [recomended]

Requires: pgdb python module

Usage: db.pgdb(host='127.0.0.1',port=5432,dbname='sagator',
               dbuser='sagator',dbpasswd='xxxxxx')

Parameters:
      host            - database server hostname
      port            - tcp socket port for database server
      dbname          - database name
      dbuser          - authorization username
      dbpasswd        - authorization password

Database creation script:     scripts/db/pgsql.sh

PostgreSQL support via psycopg python module.

Requires: psycopg python module

Usage: db.psycopg(host='127.0.0.1',port=5432,dbname='sagator',
                  dbuser='sagator',dbpasswd='xxxxxx')

Parameters:
      host            - database server hostname
      port            - tcp socket port for database server
      dbname          - database name
      dbuser          - authorization username
      dbpasswd        - authorization password

Database creation script:     scripts/db/pgsql.sh

SQLite database conenction.

Requires: sqlite python module

Usage: db.sqlite(dbname='/var/lib/sagator/sqlitedb')

Parameters:
      dbname          - database name

Database creation script:     scripts/db/sqlite.sh