WARN: more elementwise comparisons to object

Author: jreback

pandas/core/common.py

@@ -444,14 +444,24 @@ def mask_missing(arr, values_to_mask):
     mask = None
     for x in nonna:
         if mask is None:
-            mask = arr == x
+
+            # numpy elementwise comparison warning
+            if is_numeric_dtype(arr) and is_string_like(x):
+                mask = False
+            else:
+                mask = arr == x
 
             # if x is a string and arr is not, then we get False and we must
             # expand the mask to size arr.shape
             if np.isscalar(mask):
                 mask = np.zeros(arr.shape, dtype=bool)
         else:
-            mask |= arr == x
+
+            # numpy elementwise comparison warning
+            if is_numeric_dtype(arr) and is_string_like(x):
+                mask |= False
+            else:
+                mask |= arr == x
 
     if na_mask.any():
         if mask is None:
@@ -2382,6 +2392,9 @@ def _maybe_make_list(obj):
 is_complex = lib.is_complex
 
 
+def is_string_like(obj):
+    return isinstance(obj, (compat.text_type, compat.string_types))
+
 def is_iterator(obj):
     # python 3 generators have __next__ instead of next
     return hasattr(obj, 'next') or hasattr(obj, '__next__')

pandas/core/internals.py

@@ -17,7 +17,7 @@
                                 is_datetime64tz_dtype, is_datetimetz, is_sparse,
                                 array_equivalent, _maybe_convert_string_to_object,
                                 is_categorical, needs_i8_conversion, is_datetimelike_v_numeric,
-                                is_internal_type)
+                                is_string_like, is_internal_type)
 from pandas.core.dtypes import DatetimeTZDtype
 
 from pandas.core.index import Index, MultiIndex, _ensure_index
@@ -1085,6 +1085,11 @@ def get_result(other):
             # avoid numpy warning of comparisons again None
             if other is None:
                 result = not func.__name__ == 'eq'
+
+            # avoid numpy warning of elementwise comparisons to object
+            elif self.is_numeric and is_string_like(other):
+                result = False
+
             else:
                 result = func(values, other)