Source code for pyspark.ml.param

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import array
import sys
if sys.version > '3':
    basestring = str
    xrange = range
    unicode = str

from abc import ABCMeta
import copy
import numpy as np

from py4j.java_gateway import JavaObject

from pyspark.ml.linalg import DenseVector, Vector, Matrix
from pyspark.ml.util import Identifiable


__all__ = ['Param', 'Params', 'TypeConverters']


[docs]class Param(object): """ A param with self-contained documentation. .. versionadded:: 1.3.0 """ def __init__(self, parent, name, doc, typeConverter=None): if not isinstance(parent, Identifiable): raise TypeError("Parent must be an Identifiable but got type %s." % type(parent)) self.parent = parent.uid self.name = str(name) self.doc = str(doc) self.typeConverter = TypeConverters.identity if typeConverter is None else typeConverter def _copy_new_parent(self, parent): """Copy the current param to a new parent, must be a dummy param.""" if self.parent == "undefined": param = copy.copy(self) param.parent = parent.uid return param else: raise ValueError("Cannot copy from non-dummy parent %s." % parent) def __str__(self): return str(self.parent) + "__" + self.name def __repr__(self): return "Param(parent=%r, name=%r, doc=%r)" % (self.parent, self.name, self.doc) def __hash__(self): return hash(str(self)) def __eq__(self, other): if isinstance(other, Param): return self.parent == other.parent and self.name == other.name else: return False
[docs]class TypeConverters(object): """ .. note:: DeveloperApi Factory methods for common type conversion functions for `Param.typeConverter`. .. versionadded:: 2.0.0 """ @staticmethod def _is_numeric(value): vtype = type(value) return vtype in [int, float, np.float64, np.int64] or vtype.__name__ == 'long' @staticmethod def _is_integer(value): return TypeConverters._is_numeric(value) and float(value).is_integer() @staticmethod def _can_convert_to_list(value): vtype = type(value) return vtype in [list, np.ndarray, tuple, xrange, array.array] or isinstance(value, Vector) @staticmethod def _can_convert_to_string(value): vtype = type(value) return isinstance(value, basestring) or vtype in [np.unicode_, np.string_, np.str_] @staticmethod
[docs] def identity(value): """ Dummy converter that just returns value. """ return value
@staticmethod
[docs] def toList(value): """ Convert a value to a list, if possible. """ if type(value) == list: return value elif type(value) in [np.ndarray, tuple, xrange, array.array]: return list(value) elif isinstance(value, Vector): return list(value.toArray()) else: raise TypeError("Could not convert %s to list" % value)
@staticmethod
[docs] def toListFloat(value): """ Convert a value to list of floats, if possible. """ if TypeConverters._can_convert_to_list(value): value = TypeConverters.toList(value) if all(map(lambda v: TypeConverters._is_numeric(v), value)): return [float(v) for v in value] raise TypeError("Could not convert %s to list of floats" % value)
@staticmethod
[docs] def toListInt(value): """ Convert a value to list of ints, if possible. """ if TypeConverters._can_convert_to_list(value): value = TypeConverters.toList(value) if all(map(lambda v: TypeConverters._is_integer(v), value)): return [int(v) for v in value] raise TypeError("Could not convert %s to list of ints" % value)
@staticmethod
[docs] def toListString(value): """ Convert a value to list of strings, if possible. """ if TypeConverters._can_convert_to_list(value): value = TypeConverters.toList(value) if all(map(lambda v: TypeConverters._can_convert_to_string(v), value)): return [TypeConverters.toString(v) for v in value] raise TypeError("Could not convert %s to list of strings" % value)
@staticmethod
[docs] def toVector(value): """ Convert a value to a MLlib Vector, if possible. """ if isinstance(value, Vector): return value elif TypeConverters._can_convert_to_list(value): value = TypeConverters.toList(value) if all(map(lambda v: TypeConverters._is_numeric(v), value)): return DenseVector(value) raise TypeError("Could not convert %s to vector" % value)
@staticmethod
[docs] def toMatrix(value): """ Convert a value to a MLlib Matrix, if possible. """ if isinstance(value, Matrix): return value raise TypeError("Could not convert %s to matrix" % value)
@staticmethod
[docs] def toFloat(value): """ Convert a value to a float, if possible. """ if TypeConverters._is_numeric(value): return float(value) else: raise TypeError("Could not convert %s to float" % value)
@staticmethod
[docs] def toInt(value): """ Convert a value to an int, if possible. """ if TypeConverters._is_integer(value): return int(value) else: raise TypeError("Could not convert %s to int" % value)
@staticmethod
[docs] def toString(value): """ Convert a value to a string, if possible. """ if isinstance(value, basestring): return value elif type(value) in [np.string_, np.str_]: return str(value) elif type(value) == np.unicode_: return unicode(value) else: raise TypeError("Could not convert %s to string type" % type(value))
@staticmethod
[docs] def toBoolean(value): """ Convert a value to a boolean, if possible. """ if type(value) == bool: return value else: raise TypeError("Boolean Param requires value of type bool. Found %s." % type(value))
[docs]class Params(Identifiable): """ Components that take parameters. This also provides an internal param map to store parameter values attached to the instance. .. versionadded:: 1.3.0 """ __metaclass__ = ABCMeta def __init__(self): super(Params, self).__init__() #: internal param map for user-supplied values param map self._paramMap = {} #: internal param map for default values self._defaultParamMap = {} #: value returned by :py:func:`params` self._params = None # Copy the params from the class to the object self._copy_params() def _copy_params(self): """ Copy all params defined on the class to current object. """ cls = type(self) src_name_attrs = [(x, getattr(cls, x)) for x in dir(cls)] src_params = list(filter(lambda nameAttr: isinstance(nameAttr[1], Param), src_name_attrs)) for name, param in src_params: setattr(self, name, param._copy_new_parent(self)) @property
[docs] def params(self): """ Returns all params ordered by name. The default implementation uses :py:func:`dir` to get all attributes of type :py:class:`Param`. """ if self._params is None: self._params = list(filter(lambda attr: isinstance(attr, Param), [getattr(self, x) for x in dir(self) if x != "params" and not isinstance(getattr(type(self), x, None), property)])) return self._params
[docs] def explainParam(self, param): """ Explains a single param and returns its name, doc, and optional default value and user-supplied value in a string. """ param = self._resolveParam(param) values = [] if self.isDefined(param): if param in self._defaultParamMap: values.append("default: %s" % self._defaultParamMap[param]) if param in self._paramMap: values.append("current: %s" % self._paramMap[param]) else: values.append("undefined") valueStr = "(" + ", ".join(values) + ")" return "%s: %s %s" % (param.name, param.doc, valueStr)
[docs] def explainParams(self): """ Returns the documentation of all params with their optionally default values and user-supplied values. """ return "\n".join([self.explainParam(param) for param in self.params])
[docs] def getParam(self, paramName): """ Gets a param by its name. """ param = getattr(self, paramName) if isinstance(param, Param): return param else: raise ValueError("Cannot find param with name %s." % paramName)
[docs] def isSet(self, param): """ Checks whether a param is explicitly set by user. """ param = self._resolveParam(param) return param in self._paramMap
[docs] def hasDefault(self, param): """ Checks whether a param has a default value. """ param = self._resolveParam(param) return param in self._defaultParamMap
[docs] def isDefined(self, param): """ Checks whether a param is explicitly set by user or has a default value. """ return self.isSet(param) or self.hasDefault(param)
[docs] def hasParam(self, paramName): """ Tests whether this instance contains a param with a given (string) name. """ if isinstance(paramName, basestring): p = getattr(self, paramName, None) return isinstance(p, Param) else: raise TypeError("hasParam(): paramName must be a string")
[docs] def getOrDefault(self, param): """ Gets the value of a param in the user-supplied param map or its default value. Raises an error if neither is set. """ param = self._resolveParam(param) if param in self._paramMap: return self._paramMap[param] else: return self._defaultParamMap[param]
[docs] def extractParamMap(self, extra=None): """ Extracts the embedded default param values and user-supplied values, and then merges them with extra values from input into a flat param map, where the latter value is used if there exist conflicts, i.e., with ordering: default param values < user-supplied values < extra. :param extra: extra param values :return: merged param map """ if extra is None: extra = dict() paramMap = self._defaultParamMap.copy() paramMap.update(self._paramMap) paramMap.update(extra) return paramMap
[docs] def copy(self, extra=None): """ Creates a copy of this instance with the same uid and some extra params. The default implementation creates a shallow copy using :py:func:`copy.copy`, and then copies the embedded and extra parameters over and returns the copy. Subclasses should override this method if the default approach is not sufficient. :param extra: Extra parameters to copy to the new instance :return: Copy of this instance """ if extra is None: extra = dict() that = copy.copy(self) that._paramMap = {} that._defaultParamMap = {} return self._copyValues(that, extra)
[docs] def set(self, param, value): """ Sets a parameter in the embedded param map. """ self._shouldOwn(param) try: value = param.typeConverter(value) except ValueError as e: raise ValueError('Invalid param value given for param "%s". %s' % (param.name, e)) self._paramMap[param] = value
def _shouldOwn(self, param): """ Validates that the input param belongs to this Params instance. """ if not (self.uid == param.parent and self.hasParam(param.name)): raise ValueError("Param %r does not belong to %r." % (param, self)) def _resolveParam(self, param): """ Resolves a param and validates the ownership. :param param: param name or the param instance, which must belong to this Params instance :return: resolved param instance """ if isinstance(param, Param): self._shouldOwn(param) return param elif isinstance(param, basestring): return self.getParam(param) else: raise ValueError("Cannot resolve %r as a param." % param) @staticmethod def _dummy(): """ Returns a dummy Params instance used as a placeholder to generate docs. """ dummy = Params() dummy.uid = "undefined" return dummy def _set(self, **kwargs): """ Sets user-supplied params. """ for param, value in kwargs.items(): p = getattr(self, param) if value is not None: try: value = p.typeConverter(value) except TypeError as e: raise TypeError('Invalid param value given for param "%s". %s' % (p.name, e)) self._paramMap[p] = value return self def _clear(self, param): """ Clears a param from the param map if it has been explicitly set. """ if self.isSet(param): del self._paramMap[param] def _setDefault(self, **kwargs): """ Sets default params. """ for param, value in kwargs.items(): p = getattr(self, param) if value is not None and not isinstance(value, JavaObject): try: value = p.typeConverter(value) except TypeError as e: raise TypeError('Invalid default param value given for param "%s". %s' % (p.name, e)) self._defaultParamMap[p] = value return self def _copyValues(self, to, extra=None): """ Copies param values from this instance to another instance for params shared by them. :param to: the target instance :param extra: extra params to be copied :return: the target instance with param values copied """ paramMap = self._paramMap.copy() if extra is not None: paramMap.update(extra) for param in self.params: # copy default params if param in self._defaultParamMap and to.hasParam(param.name): to._defaultParamMap[to.getParam(param.name)] = self._defaultParamMap[param] # copy explicitly set params if param in paramMap and to.hasParam(param.name): to._set(**{param.name: paramMap[param]}) return to def _resetUid(self, newUid): """ Changes the uid of this instance. This updates both the stored uid and the parent uid of params and param maps. This is used by persistence (loading). :param newUid: new uid to use, which is converted to unicode :return: same instance, but with the uid and Param.parent values updated, including within param maps """ newUid = unicode(newUid) self.uid = newUid newDefaultParamMap = dict() newParamMap = dict() for param in self.params: newParam = copy.copy(param) newParam.parent = newUid if param in self._defaultParamMap: newDefaultParamMap[newParam] = self._defaultParamMap[param] if param in self._paramMap: newParamMap[newParam] = self._paramMap[param] param.parent = newUid self._defaultParamMap = newDefaultParamMap self._paramMap = newParamMap return self