Emitter class reference¶

This document covers features of the BaseEmitter class. Currently the system has two emitter CSVEmitter and MySQLEmitter implemented, of which the last is the default emitter. An emitter provides the export format for the scanned and cleaned datasets. It also provides preambles in the output files, for example to clean the target table before loading it.

The basic structure for emitting is a combination between manager and emitter:

e = Emitter(manager=Model.objects)
print e.preamble(header=[..my header lines to add..])
for l in Model.objects.all():
  print e.emit(l)  # emit is returning a list of strings!

Note

At this moment data-migrator is not an active part in schema migrations of any sort. It is purely about cleaning and transforming data (yet!).

MySQLEmitter¶

class data_migrator.emitters.mysql.MySQLEmitter(*args, **kwargs)¶

MySQL emitter to output MySQL specific insert statements

base_template¶: base template to output the object

extension¶: str – file extension for output file of this emitter

emit(l)¶: Output the result set of an object as MYSQL insert statement

preamble(headers)¶: override the preamble method to make it specific for MySQL

CSVEmitter¶

class data_migrator.emitters.csv.CSVEmitter(*args, **kwargs)¶

CSV emitter to output delimited data

base_template¶: base template to output the object

extension¶: str – file extension for output file of this emitter

emit(l)¶: Output the result set of an object as CSV string

BaseEmitter¶

class data_migrator.emitters.base.BaseEmitter(extension=None, manager=None)¶

Base for emitters of the data_migrator.

manager¶: BaseManager – reference to the manager that is calling this emitter to export objects from that manager

model_class¶: Model – reference to the model linked to the class

extension¶: str – file extension for output file of this emitter

note: model_class and manager are linked together

emit(o)¶

output the result set of an object.

Parameters:	o (Model) – object to transform
Returns:	generated strings
Return type:	list

filename()¶

generate filename for this emitter.

generates a filename bases on BaseEmitter.extension and either file_name or table_name

Returns:	filename
Return type:	str

preamble(headers)¶

generate a premable for the file to emit.

Parameters:	headers (list) – additional header to provide outside the emitter (e.g. statistics)
Returns:	preamble lines
Return type:	list