diff options
Diffstat (limited to 'python/pyspark/ml/param/__init__.py')
| -rw-r--r-- | python/pyspark/ml/param/__init__.py | 146 |
1 files changed, 127 insertions, 19 deletions
diff --git a/python/pyspark/ml/param/__init__.py b/python/pyspark/ml/param/__init__.py index e3a53dd780..5c62620562 100644 --- a/python/pyspark/ml/param/__init__.py +++ b/python/pyspark/ml/param/__init__.py @@ -25,23 +25,21 @@ __all__ = ['Param', 'Params'] class Param(object): """ - A param with self-contained documentation and optionally default value. + A param with self-contained documentation. """ - def __init__(self, parent, name, doc, defaultValue=None): - if not isinstance(parent, Identifiable): - raise ValueError("Parent must be identifiable but got type %s." % type(parent).__name__) + def __init__(self, parent, name, doc): + if not isinstance(parent, Params): + raise ValueError("Parent must be a Params but got type %s." % type(parent).__name__) self.parent = parent self.name = str(name) self.doc = str(doc) - self.defaultValue = defaultValue def __str__(self): - return str(self.parent) + "-" + self.name + return str(self.parent) + "__" + self.name def __repr__(self): - return "Param(parent=%r, name=%r, doc=%r, defaultValue=%r)" % \ - (self.parent, self.name, self.doc, self.defaultValue) + return "Param(parent=%r, name=%r, doc=%r)" % (self.parent, self.name, self.doc) class Params(Identifiable): @@ -52,26 +50,128 @@ class Params(Identifiable): __metaclass__ = ABCMeta - def __init__(self): - super(Params, self).__init__() - #: embedded param map - self.paramMap = {} + #: internal param map for user-supplied values param map + paramMap = {} + + #: internal param map for default values + defaultParamMap = {} @property def params(self): """ - Returns all params. The default implementation uses - :py:func:`dir` to get all attributes of type + Returns all params ordered by name. The default implementation + uses :py:func:`dir` to get all attributes of type :py:class:`Param`. """ return filter(lambda attr: isinstance(attr, Param), [getattr(self, x) for x in dir(self) if x != "params"]) - def _merge_params(self, params): - paramMap = self.paramMap.copy() - paramMap.update(params) + def _explain(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) + + def explainParams(self): + """ + Returns the documentation of all params with their optionally + default values and user-supplied values. + """ + return "\n".join([self._explain(param) for param in self.params]) + + 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) + + def isSet(self, param): + """ + Checks whether a param is explicitly set by user. + """ + param = self._resolveParam(param) + return param in self.paramMap + + def hasDefault(self, param): + """ + Checks whether a param has a default value. + """ + param = self._resolveParam(param) + return param in self.defaultParamMap + + 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) + + def getOrDefault(self, param): + """ + Gets the value of a param in the user-supplied param map or its + default value. Raises an error if either is set. + """ + if isinstance(param, Param): + if param in self.paramMap: + return self.paramMap[param] + else: + return self.defaultParamMap[param] + elif isinstance(param, str): + return self.getOrDefault(self.getParam(param)) + else: + raise KeyError("Cannot recognize %r as a param." % param) + + def extractParamMap(self, extraParamMap={}): + """ + 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 < extraParamMap. + :param extraParamMap: extra param values + :return: merged param map + """ + paramMap = self.defaultParamMap.copy() + paramMap.update(self.paramMap) + paramMap.update(extraParamMap) return paramMap + def _shouldOwn(self, param): + """ + Validates that the input param belongs to this Params instance. + """ + if param.parent is not self: + 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, str): + return self.getParam(param) + else: + raise ValueError("Cannot resolve %r as a param." % param) + @staticmethod def _dummy(): """ @@ -81,10 +181,18 @@ class Params(Identifiable): dummy.uid = "undefined" return dummy - def _set_params(self, **kwargs): + def _set(self, **kwargs): """ - Sets params. + Sets user-supplied params. """ for param, value in kwargs.iteritems(): self.paramMap[getattr(self, param)] = value return self + + def _setDefault(self, **kwargs): + """ + Sets default params. + """ + for param, value in kwargs.iteritems(): + self.defaultParamMap[getattr(self, param)] = value + return self |