Adapt to new location of pandas is_categorical_dtype

njsmith · njsmith · commit 6c73617b0727 · 2016-10-12T20:59:06.000-07:00
I'm not sure what version this changed in, but originally the only way
to get is_categorical_dtype was as a private export from
pandas.core.common. Now that's deprecated, and you're supposed to get it
from pandas.api.type. We try both, to cover both periods.
diff --git a/.travis.yml b/.travis.yml
@@ -12,6 +12,12 @@ matrix:
       env: PANDAS_VERSION_STR="=0.14.0 libgfortran=1.0"
     - python: 2.7
       env: PANDAS_VERSION_STR="=0.14.0 libgfortran=1.0"
+    # 0.18.0 has is_categorical_dtype in a different place than 0.19.0+
+    - python: 3.4
+      env: PANDAS_VERSION_STR="=0.18.0"
+    - python: 2.7
+      env: PANDAS_VERSION_STR="=0.18.0"
+
 # This disables sudo, but makes builds start much faster
 # See http://blog.travis-ci.com/2014-12-17-faster-builds-with-container-based-infrastructure/
 sudo: false
diff --git a/patsy/util.py b/patsy/util.py
@@ -40,9 +40,20 @@
 # Can drop this guard whenever we drop support for such older versions of
 # pandas.
 have_pandas_categorical = (have_pandas and hasattr(pandas, "Categorical"))
-have_pandas_categorical_dtype = (have_pandas
-                                  and hasattr(pandas.core.common,
-                                              "is_categorical_dtype"))
+if not have_pandas:
+    have_pandas_categorical_dtype = False
+    _pandas_is_categorical_dtype = None
+else:
+    if hasattr(pandas, "api"):
+        # This is available starting in pandas v0.19.0
+        have_pandas_categorical_dtype = True
+        _pandas_is_categorical_dtype = pandas.api.types.is_categorical_dtype
+    else:
+        # This is needed for pandas v0.18.0 and earlier
+        _pandas_is_categorical_dtype = getattr(pandas.core.common,
+                                               "is_categorical_dtype", None)
+        have_pandas_categorical_dtype = (_pandas_is_categorical_dtype
+                                         is not None)
 
 # Passes through Series and DataFrames, call np.asarray() on everything else
 def asarray_or_pandas(a, copy=False, dtype=None, subok=False):
@@ -637,10 +648,7 @@ def test_pandas_Categorical_accessors():
 def safe_is_pandas_categorical_dtype(dt):
     if not have_pandas_categorical_dtype:
         return False
-    # WTF this incredibly crucial function is not even publically exported.
-    # Also if you read its source it uses a bare except: block which is broken
-    # by definition, but oh well there is not much I can do about this.
-    return pandas.core.common.is_categorical_dtype(dt)
+    return _pandas_is_categorical_dtype(dt)
 
 # Needed to support pandas >= 0.15 (!)
 def safe_is_pandas_categorical(data):
