# `DBAdapters` – database adapters for statistics

Warning

the use the of a DB Adapter can reduce the performance of the Genetic Algorithm.

Pyevolve have a feature in which you can save the statistics of every generation in a database, file or call an URL with the statistics as param. You can use the database to plot evolution statistics graphs later. In this module, you’ll find the adapters above cited.

See also

Method `GSimpleGA.GSimpleGA.setDBAdapter()`
  DB Adapters are set in the GSimpleGA Class.

class `DBAdapters.``DBBaseAdapter`(frequency, identify)

  DBBaseAdapter Class - The base class for all DB Adapters

  If you want to create your own DB Adapter, you must subclass this class.

  Parameters: | frequency – the the generational dump frequency

  New in version 0.6: Added the `DBBaseAdapter` class.

  `commitAndClose`()

    This method is called at the end of the evolution, to closes the DB Adapter and commit the changes

  `getIdentify`()

    Return the statistics identify

    Return type: | identify string

  `getStatsGenFreq`()

    Returns the frequency of statistical dump

    Return type: | the generation interval of statistical dump

  `insert`(ga_engine)

    Insert the stats

    Parameters: | ga_engine – the GA Engine

  `open`(ga_engine)

    This method is called one time to do the initialization of the DB Adapter

    Parameters: | ga_engine – the GA Engine

  `setIdentify`(identify)

    Sets the identify of the statistics

    Parameters: | identify – the id string

  `setStatsGenFreq`(statsGenFreq)

    Set the frequency of statistical dump

    Parameters: | statsGenFreq – the generation interval of statistical dump

class `DBAdapters.``DBFileCSV`(filename='pyevolve.csv', identify=None, frequency=1, reset=True)

  DBFileCSV Class - Adapter to dump statistics in CSV format

  Inheritance diagram for `DBAdapters.DBFileCSV`:

  Example:

        >>> adapter = DBFileCSV(filename="file.csv", identify="run_01",
                                frequency = 1, reset = True)

    param filename: | the CSV filename
    param identify: | the identify of the run
    param frequency:
    | the generational dump frequency
    param reset: | if is True, the file old data will be overwrite with the new

  New in version 0.6: Removed the stub methods and subclassed the `DBBaseAdapter` class.

  `close`()

    Closes the CSV file handle

  `commitAndClose`()

    Commits and closes

  `getIdentify`()

    Return the statistics identify

    Return type: | identify string

  `getStatsGenFreq`()

    Returns the frequency of statistical dump

    Return type: | the generation interval of statistical dump

  `insert`(ga_engine)

    Inserts the stats into the CSV file

    Parameters: | ga_engine – the GA Engine

    Changed in version 0.6: The method now receives the ga_engine parameter.

  `open`(ga_engine)

    Open the CSV file or creates a new file

    Parameters: | ga_engine – the GA Engine

    Changed in version 0.6: The method now receives the ga_engine parameter.

  `setIdentify`(identify)

    Sets the identify of the statistics

    Parameters: | identify – the id string

  `setStatsGenFreq`(statsGenFreq)

    Set the frequency of statistical dump

    Parameters: | statsGenFreq – the generation interval of statistical dump

class `DBAdapters.``DBMySQLAdapter`(user, passwd, host='localhost', port=3306, db='pyevolve', identify=None, resetDB=False, resetIdentify=True, frequency=1, commit_freq=300)

  DBMySQLAdapter Class - Adapter to dump data in MySql database server

  Inheritance diagram for `DBAdapters.DBMySQLAdapter`:

  Example:

        >>> dbadapter = DBMySQLAdapter("pyevolve_username", "password", identify="run1")

  or

      >>> dbadapter = DBMySQLAdapter(user="username", passwd="password",
      ...                            host="mysqlserver.com.br", port=3306, db="pyevolve_db")

  When you run some GA for the first time, you need to create the database, for this, you must use the resetDB parameter as True.

  This parameter will erase all the database tables and will create the new ones. The resetDB parameter is different from the resetIdentify parameter, the resetIdentify only erases the rows with the same “identify” name, and resetDB will drop and recreate the tables.

  Parameters:

  - user – mysql username (must have permission to create, drop, insert, etc.. on tables
  - passwd – the user password on MySQL server
  - host – the hostname, default is “localhost”
  - port – the port, default is 3306
  - db – the database name, default is “pyevolve”
  - identify – the identify if the run
  - resetDB – if True, the database structure will be recreated
  - resetIdentify – if True, the identify with the same name will be overwrite with new data
  - frequency – the generational dump frequency
  - commit_freq – the commit frequency

  `close`()

    Close the database connection

  `commit`()

    Commit changes to database

  `commitAndClose`()

    Commit changes on database and closes connection

  `createStructure`(stats)

    Create table using the Statistics class structure

    Parameters: | stats – the statistics object

  `getCursor`()

    Return a cursor from the pool

    Return type: | the cursor

  `getIdentify`()

    Return the statistics identify

    Return type: | identify string

  `getStatsGenFreq`()

    Returns the frequency of statistical dump

    Return type: | the generation interval of statistical dump

  `insert`(ga_engine)

    Inserts the statistics data to database

    Parameters: | ga_engine – the GA Engine

    Changed in version 0.6: The method now receives the ga_engine parameter.

  `open`(ga_engine)

    Open the database connection

    Parameters: | ga_engine – the GA Engine

    Changed in version 0.6: The method now receives the ga_engine parameter.

  `resetStructure`(stats)

    Deletes de current structure and calls createStructure

    Parameters: | stats – the statistics object

  `resetTableIdentify`()

    Delete all records on the table with the same Identify

  `setIdentify`(identify)

    Sets the identify of the statistics

    Parameters: | identify – the id string

  `setStatsGenFreq`(statsGenFreq)

    Set the frequency of statistical dump

    Parameters: | statsGenFreq – the generation interval of statistical dump

class `DBAdapters.``DBSQLite`(dbname='pyevolve.db', identify=None, resetDB=False, resetIdentify=True, frequency=1, commit_freq=300)

  DBSQLite Class - Adapter to dump data in SQLite3 database format

  Inheritance diagram for `DBAdapters.DBSQLite`:

  Example:

        >>> dbadapter = DBSQLite(identify="test")

  When you run some GA for the first time, you need to create the database, for this, you must use the resetDB parameter:

      >>> dbadapter = DBSQLite(identify="test", resetDB=True)

  This parameter will erase all the database tables and will create the new ones. The resetDB parameter is different from the resetIdentify parameter, the resetIdentify only erases the rows with the same “identify” name.

  Parameters:

  - dbname – the database filename
  - identify – the identify if the run
  - resetDB – if True, the database structure will be recreated
  - resetIdentify – if True, the identify with the same name will be overwrite with new data
  - frequency – the generational dump frequency
  - commit_freq – the commit frequency

  `close`()

    Close the database connection

  `commit`()

    Commit changes to database

  `commitAndClose`()

    Commit changes on database and closes connection

  `createStructure`(stats)

    Create table using the Statistics class structure

    Parameters: | stats – the statistics object

  `getCursor`()

    Return a cursor from the pool

    Return type: | the cursor

  `getIdentify`()

    Return the statistics identify

    Return type: | identify string

  `getStatsGenFreq`()

    Returns the frequency of statistical dump

    Return type: | the generation interval of statistical dump

  `insert`(ga_engine)

    Inserts the statistics data to database

    Parameters: | ga_engine – the GA Engine

    Changed in version 0.6: The method now receives the ga_engine parameter.

  `open`(ga_engine)

    Open the database connection

    Parameters: | ga_engine – the GA Engine

    Changed in version 0.6: The method now receives the ga_engine parameter.

  `resetStructure`(stats)

    Deletes de current structure and calls createStructure

    Parameters: | stats – the statistics object

  `resetTableIdentify`()

    Delete all records on the table with the same Identify

  `setIdentify`(identify)

    Sets the identify of the statistics

    Parameters: | identify – the id string

  `setStatsGenFreq`(statsGenFreq)

    Set the frequency of statistical dump

    Parameters: | statsGenFreq – the generation interval of statistical dump

class `DBAdapters.``DBURLPost`(url, identify=None, frequency=100, post=True)

  DBURLPost Class - Adapter to call an URL with statistics

  Inheritance diagram for `DBAdapters.DBURLPost`:

  Example:

        >>> dbadapter = DBURLPost(url="http://localhost/post.py", identify="test")

  The parameters that will be sent is all the statistics described in the `Statistics.Statistics` class, and the parameters:

  generation
    The generation of the statistics
  identify
    The id specified by user

  Note

  see the `Statistics.Statistics` documentation.

  Parameters:

  - url – the URL to be used
  - identify – the identify of the run
  - frequency – the generational dump frequency
  - post – if True, the POST method will be used, otherwise GET will be used.

  New in version 0.6: Removed the stub methods and subclassed the `DBBaseAdapter` class.

  `commitAndClose`()

    This method is called at the end of the evolution, to closes the DB Adapter and commit the changes

  `getIdentify`()

    Return the statistics identify

    Return type: | identify string

  `getStatsGenFreq`()

    Returns the frequency of statistical dump

    Return type: | the generation interval of statistical dump

  `insert`(ga_engine)

    Sends the data to the URL using POST or GET

    Parameters: | ga_engine – the GA Engine

    Changed in version 0.6: The method now receives the ga_engine parameter.

  `open`(ga_engine)

    Load the modules needed

    Parameters: | ga_engine – the GA Engine

    Changed in version 0.6: The method now receives the ga_engine parameter.

  `setIdentify`(identify)

    Sets the identify of the statistics

    Parameters: | identify – the id string

  `setStatsGenFreq`(statsGenFreq)

    Set the frequency of statistical dump

    Parameters: | statsGenFreq – the generation interval of statistical dump

class `DBAdapters.``DBVPythonGraph`(identify=None, frequency=20, genmax=False)

  The DBVPythonGraph Class - A DB Adapter for real-time visualization using VPython

  Inheritance diagram for `DBAdapters.DBVPythonGraph`:

  Note

  to use this DB Adapter, you must install VPython first.

  Example:

        >>> adapter = DBAdapters.DBVPythonGraph(identify="run_01", frequency = 1)
        >>> ga_engine.setDBAdapter(adapter)

  Parameters:

  - identify – the identify of the run
  - genmax – use the generations as max value for x-axis, default False
  - frequency – the generational dump frequency

  New in version 0.6: The DBVPythonGraph class.

  `commitAndClose`()

    This method is called at the end of the evolution, to closes the DB Adapter and commit the changes

  `getIdentify`()

    Return the statistics identify

    Return type: | identify string

  `getStatsGenFreq`()

    Returns the frequency of statistical dump

    Return type: | the generation interval of statistical dump

  `insert`(ga_engine)

    Plot the current statistics to the graphs

    Parameters: | ga_engine – the GA Engine

  `makeDisplay`(title_sec, x, y, ga_engine)

    Used internally to create a new display for VPython.

    Parameters:

    - title_sec – the title of the window
    - x – the x position of the window
    - y – the y position of the window
    - ga_engine – the GA Engine

    Return type: | the window (the return of gdisplay call)

  `open`(ga_engine)

    Imports the VPython module and creates the four graph windows

    Parameters: | ga_engine – the GA Engine

  `setIdentify`(identify)

    Sets the identify of the statistics

    Parameters: | identify – the id string

  `setStatsGenFreq`(statsGenFreq)

    Set the frequency of statistical dump

    Parameters: | statsGenFreq – the generation interval of statistical dump

class `DBAdapters.``DBXMLRPC`(url, identify=None, frequency=20)

  DBXMLRPC Class - Adapter to dump statistics to a XML Remote Procedure Call

  Inheritance diagram for `DBAdapters.DBXMLRPC`:

  Example:

        >>> adapter = DBXMLRPC(url="http://localhost:8000/", identify="run_01",
                               frequency = 1)

    param url: | the URL of the XML RPC
    param identify: | the identify of the run
    param frequency:
    | the generational dump frequency

  Note

  The XML RPC Server must implement the insert method, wich receives a python dictionary as argument.

  Example of an server in Python:

      import xmlrpclib
      from SimpleXMLRPCServer import SimpleXMLRPCServer

      def insert(l):
          print "Received statistics: %s" % l

      server = SimpleXMLRPCServer(("localhost", 8000), allow_none=True)
      print "Listening on port 8000..."
      server.register_function(insert, "insert")
      server.serve_forever()

  New in version 0.6: The `DBXMLRPC` class.

  `commitAndClose`()

    This method is called at the end of the evolution, to closes the DB Adapter and commit the changes

  `getIdentify`()

    Return the statistics identify

    Return type: | identify string

  `getStatsGenFreq`()

    Returns the frequency of statistical dump

    Return type: | the generation interval of statistical dump

  `insert`(ga_engine)

    Calls the XML RPC procedure

    Parameters: | ga_engine – the GA Engine

    Changed in version 0.6: The method now receives the ga_engine parameter.

  `open`(ga_engine)

    Open the XML RPC Server proxy

    Parameters: | ga_engine – the GA Engine

    Changed in version 0.6: The method now receives the ga_engine parameter.

  `setIdentify`(identify)

    Sets the identify of the statistics

    Parameters: | identify – the id string

  `setStatsGenFreq`(statsGenFreq)

    Set the frequency of statistical dump

    Parameters: | statsGenFreq – the generation interval of statistical dump