CLN: update asv benchmarks to reflect astype categorical deprecation

Author: qwhelan

asv_bench/benchmarks/categoricals.py

@@ -132,16 +132,18 @@ def setup(self):
         ncats = 100
 
         self.s_str = pd.Series(tm.makeCategoricalIndex(N, ncats)).astype(str)
-        self.s_str_cat = self.s_str.astype('category')
+        self.s_str_cat = pd.Series(self.s_str, dtype='category')
         with warnings.catch_warnings(record=True):
-            self.s_str_cat_ordered = self.s_str.astype('category',
-                                                       ordered=True)
+            str_cat_type = pd.CategoricalDtype(set(self.s_str),
+                                               ordered=True)
+            self.s_str_cat_ordered = self.s_str.astype(str_cat_type)
 
         self.s_int = pd.Series(np.random.randint(0, ncats, size=N))
-        self.s_int_cat = self.s_int.astype('category')
+        self.s_int_cat = pd.Series(self.s_int, dtype='category')
         with warnings.catch_warnings(record=True):
-            self.s_int_cat_ordered = self.s_int.astype('category',
-                                                       ordered=True)
+            int_cat_type = pd.Categorical(set(self.s_int),
+                                          ordered=True)
+            self.s_int_cat_ordered = self.s_int.astype(int_cat_type)
 
     def time_rank_string(self):
         self.s_str.rank()