FIX make pipeline memory compatible with older joblib version (#687)

Co-authored-by: Guillaume Lemaitre <g.lemaitre58@gmail.com>

Author: chkoar

doc/whats_new/v0.7.rst

@@ -1,11 +1,18 @@
 .. _changes_0_7:
 
-Version 0.7.0 (under development)
-=================================
+Version 0.7.0
+=============
 
 Changelog
 ---------
 
+Maintenance
+...........
+
+- Ensure that :class:`imblearn.pipeline.Pipeline` is working when `memory`
+ is activated and `joblib==0.11`.
+ :pr:`687` by :user:`Christos Aridas <chkoar>`.
+
 Changed models
 ..............
 

imblearn/pipeline.py

@@ -213,22 +213,15 @@ def _fit(self, X, y=None, **fit_params):
  with _print_elapsed_time('Pipeline',
  self._log_message(step_idx)):
  continue
- if hasattr(memory, "location"):
+
+ try:
  # joblib >= 0.12
- if memory.location is None:
- # we do not clone when caching is disabled to
- # preserve backward compatibility
- cloned_transformer = transformer
- else:
- cloned_transformer = clone(transformer)
- elif hasattr(memory, "cachedir"):
- # joblib <= 0.11
- if memory.cachedir is None:
- # we do not clone when caching is disabled to
- # preserve backward compatibility
- cloned_transformer = transformer
- else:
- cloned_transformer = clone(transformer)
+ mem = memory.location
+ except AttributeError:
+ mem = memory.cachedir
+ finally:
+ cloned_transformer = clone(transformer) if mem else transformer
+
  # Fit or load from cache the current transfomer
  if hasattr(cloned_transformer, "transform") or hasattr(
  cloned_transformer, "fit_transform"

imblearn/tests/test_pipeline.py

@@ -1342,3 +1342,22 @@ def test_pipeline_score_samples_pca_lof():
  # Check the values
  lof.fit(pca.fit_transform(X))
  assert_allclose(pipe.score_samples(X), lof.score_samples(pca.transform(X)))
+
+
+def test_pipeline_old_joblib_memory(monkeypatch):
+ """Test that Pipeline works with old versions of joblib"""
+
+ monkeypatch.setattr(Memory, "cachedir", "foo", raising=False)
+ monkeypatch.setattr(Memory, "cache", lambda self, x: x, raising=False)
+ memory = Memory()
+
+ del memory.location # Older versions do not have the location parameter
+
+ iris = load_iris()
+ X = iris.data
+ y = iris.target
+
+ cached_pipe = Pipeline(
+ [("transf", DummyTransf()), ("svc", SVC(gamma="scale"))], memory=memory
+ )
+ cached_pipe.fit(X, y)