From 47a0383775cc0799ba0b1f7f0e9a658c05c6ca44 Mon Sep 17 00:00:00 2001
From: Johannes Weytjens <34494702+jpweytjens@users.noreply.github.com>
Date: Sun, 1 Dec 2019 15:56:25 +0100
Subject: [PATCH] Initialize Compare with (a list of) features (bugfix) (#124)

---
 recordlinkage/base.py | 11 ++++++++---
 tests/test_compare.py | 20 ++++++++++++++++++++
 2 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/recordlinkage/base.py b/recordlinkage/base.py
index aae7576c..7deca0d0 100755
--- a/recordlinkage/base.py
+++ b/recordlinkage/base.py
@@ -23,6 +23,7 @@
                                  index_split,
                                  frame_indexing)
 from recordlinkage.types import (is_numpy_like,
+                                 is_list_like,
                                  is_pandas_2d_multiindex)
 from recordlinkage.measures import max_pairs
 from recordlinkage.utils import DeprecationHelper, LearningError
@@ -285,7 +286,7 @@ def _dedup_index(self, df_a):
             pairs = pairs[pairs.codes[0] > pairs.codes[1]]
         except AttributeError:
             # backwards compat pandas <24
-            pairs = pairs[pairs.labels[0] > pairs.labels[1]] 
+            pairs = pairs[pairs.labels[0] > pairs.labels[1]]
 
         return pairs
 
@@ -543,7 +544,6 @@ def __init__(self, features=[], n_jobs=1, indexing_type='label',
         else:
             self.n_jobs = n_jobs
         self.indexing_type = indexing_type  # label of position
-        self.features = []
 
         # logging
         self._i = 1
@@ -582,7 +582,10 @@ def add(self, model):
             A (list of) compare feature(s) from
             :mod:`recordlinkage.compare`.
         """
-        self.features.append(model)
+        if isinstance(model, list):
+            self.features.extend(model)
+        else:
+            self.features.append(model)
 
     def compare_vectorized(self, comp_func, labels_left, labels_right,
                            *args, **kwargs):
@@ -766,6 +769,8 @@ def _union(self, objs, index=None, column_i=0):
             if isinstance(feat, tuple):
                 if label is None:
                     label = [None] * len(feat)
+                if not is_list_like(label):
+                    label = (label,)
 
                 partial_result = self._union(
                     zip(feat, label), column_i=column_i)
diff --git a/tests/test_compare.py b/tests/test_compare.py
index 8938f3cf..91274d11 100644
--- a/tests/test_compare.py
+++ b/tests/test_compare.py
@@ -566,6 +566,26 @@ def test_indexing_types(self):
 
         pdt.assert_frame_equal(result_label, result_position)
 
+    def test_pass_list_of_features(self):
+
+        from recordlinkage.compare import FrequencyA, VariableA, VariableB
+
+        # setup datasets and record pairs
+        A = DataFrame({'col': ['abc', 'abc', 'abc', 'abc', 'abc']})
+        B = DataFrame({'col': ['abc', 'abc', 'abc', 'abc', 'abc']})
+        ix = MultiIndex.from_arrays([np.arange(5), np.arange(5)])
+
+        # test with label indexing type
+
+        features = [
+            VariableA('col', label='y1'),
+            VariableB('col', label='y2'),
+            FrequencyA('col', label='y3')
+        ]
+        comp_label = recordlinkage.Compare(features=features)
+        result_label = comp_label.compute(ix, A, B)
+
+        assert list(result_label) == ["y1", "y2", "y3"]
 
 class TestCompareFeatures(TestData):
     def test_feature(self):