Class BaseTable

source code

         object --+    
                  |    
base.meta.MetaMixin --+
                      |
         object --+   |
                  |   |
  common.ParamMixin --+
                      |
                     BaseTable

Known Subclasses:

• dbtable.DBTable
• , InMemoryTable
• , qtable.QueryTable

is a container for row data.

Tables consist of rows, where each row maps column names to their value for that row. The rows are accessible at least by iterating over a table.

Tables get constructed with a tableDef and keyword arguments. For convenience, tables must accept any keyword argument and only pluck those out it wants.

Here's a list of keywords used by BaseTables or known subclasses:

• validateRows -- have rows be validated by the tableDef before addition (all Tables)
• rows -- a list of rows the table has at start (InMemoryTables; DbTables will raise an error on these).
• connection -- a database connection to use for accessing DbTables.
• votCasts -- a dictionary mapping column names to dictionaries overriding keys of valuemappers.AnnontatedColumn.
• params -- a dictionary mapping param keys to values, where python values and literals allowed.

You can add rows using the addRow method. For bulk additions, however, it may be much more efficient to call getFeeder (though for in-memory tables, there is no advantage).

Tables can run "scripts" if someone furnishes them with a _runScripts method. This currently is only done for DBTables. See Scripting_.

Initial Metadata is populated from the tableDef.

Tables have to implement the following methods:

• __iter__
• __len__
• __getitem__(n) -- returns the n-th row or raises an IndexError
• removeRow(row) removes a row from the table or raises an IndexError if the row does not exist. This is a slow, O(n) operation.
• addRow(row) -- appends new data to the table
• getRow(*args) -- returns a row by the primary key. If no primary key is defined, a ValueError is raised, if the key is not present, a KeyError. An atomic primary key is accessed through its value, for compound primary keys a tuple must be passed.
• getFeeder(**kwargs) -> feeder object -- returns an object with add and exit methods. See feeder above.
• importFinished() -> None -- called when a feeder exits successfully
• importFailed(*excInfo) -> boolean -- called when feeding has failed; when returning True, the exception that has caused the failure is not propagated.
• close() -> may be called by clients to signify the table will no longer be used and resources should be cleared (e.g., for DBTables with private connections).