Add set_param check and test

absolutelyNoWarranty · absolutelyNoWarranty · commit f66f1cf23564 · 2017-08-19T20:06:00.000+08:00
Add check_set_params to test_common
diff --git a/sklearn/utils/estimator_checks.py b/sklearn/utils/estimator_checks.py
@@ -226,6 +226,7 @@ def _yield_all_checks(name, estimator):
     yield check_fit1d_1feature
     yield check_fit1d_1sample
     yield check_get_params_invariance
+    yield check_set_params
     yield check_dict_unchanged
     yield check_dont_overwrite_parameters
 
@@ -1720,6 +1721,47 @@ def transform(self, X):
                     shallow_params.items()))
 
 
+@ignore_warnings(category=(DeprecationWarning, FutureWarning))
+def check_set_params(name, estimator_orig):
+    if name in META_ESTIMATORS:
+        return
+    estimator = clone(estimator_orig)
+
+    # Trivial check to make sure set_params is working
+    params = estimator.get_params()
+    estimator.set_params(**params)
+
+    # Check that get_params() returns the same thing
+    # before and after set_params() with some fuzz
+    # values
+
+    estimator = clone(estimator_orig)
+    test_values = [-np.inf, np.inf, None,
+                   -100, 100, -0.5, 0.5, 0,
+                   "", "value",
+                   ('a', 'b'), {'key': 'value'}]
+
+    for param_name in params.keys():
+        for value in test_values:
+
+            try:
+                estimator.set_params(**{param_name: value})
+                get_value = estimator.get_params()[param_name]
+            except:
+                # triggered some parameter validation
+                # continue checking other test values
+                pass
+            else:
+                errmsg = ("get_params does not match set_params: "
+                          "called set_params of {0} with {1}={2} "
+                          "but get_params returns {1}={3}")
+                errmsg = errmsg.format(name, param_name, value,
+                                       get_value)
+                assert_equal(value, get_value, errmsg)
+
+        estimator = clone(estimator_orig)
+
+
 @ignore_warnings(category=(DeprecationWarning, FutureWarning))
 def check_classifiers_regression_target(name, estimator_orig):
     # Check if classifier throws an exception when fed regression targets
diff --git a/sklearn/utils/tests/test_estimator_checks.py b/sklearn/utils/tests/test_estimator_checks.py
@@ -71,6 +71,39 @@ def fit(self, X, y=None):
         return self
 
 
+class NoSetter(BaseEstimator):
+    def __init__(self, p=0):
+        self._p = p
+
+    @property
+    def p(self):
+        return self._p
+
+    def fit(self, X, y=None):
+        X, y = check_X_y(X, y)
+        return self
+
+
+class BadGetter(BaseEstimator):
+    def __init__(self, p=0):
+        self._p = p
+
+    @property
+    def p(self):
+        if self._p < 0:
+            return 0
+        else:
+            return self._p
+
+    @p.setter
+    def p(self, value):
+        self._p = value
+
+    def fit(self, X, y=None):
+        X, y = check_X_y(X, y)
+        return self
+
+
 class NoCheckinPredict(BaseBadClassifier):
     def fit(self, X, y):
         X, y = check_X_y(X, y)
@@ -129,6 +162,11 @@ def test_check_estimator():
     msg = "it does not implement a 'get_params' methods"
     assert_raises_regex(TypeError, msg, check_estimator, object)
     assert_raises_regex(TypeError, msg, check_estimator, object())
+    # check that properties can be set
+    msg = "can't set attribute"
+    assert_raises_regex(AttributeError, msg, check_estimator, NoSetter)
+    msg = "get_params does not match set_params"
+    assert_raises_regex(AssertionError, msg, check_estimator, BadGetter())
     # check that we have a fit method
     msg = "object has no attribute 'fit'"
     assert_raises_regex(AttributeError, msg, check_estimator, BaseEstimator)
