Add ASVs

asv_bench/benchmarks/array.py

@@ -2,6 +2,8 @@
 
 import pandas as pd
 
+from .pandas_vb_common import tm
+
 
 class BooleanArray:
     def setup(self):

asv_bench/benchmarks/strings.py

@@ -7,6 +7,21 @@
 from .pandas_vb_common import tm
 
 
+class Construction:
+
+    params = ["str", "string"]
+    param_names = ["dtype"]
+
+    def setup(self):
+        self.data = tm.rands_array(nchars=10 ** 5, size=10)
+
+    def time_construction(self, dtype):
+        Series(self.data, dtype=dtype)
+
+    def peakmem_construction(self, dtype):
+        Series(self.data, dtype=dtype)
+
+
 class Methods:
     def setup(self):
         self.s = Series(tm.makeStringIndex(10 ** 5))

pandas/_libs/lib.pyx

@@ -619,7 +619,7 @@ def astype_intsafe(ndarray[object] arr, new_dtype):
 @cython.wraparound(False)
 @cython.boundscheck(False)
 cpdef ndarray[object] ensure_string_array(
-        ndarray arr,
+        arr,
         object na_value=np.nan,
         bint convert_na_value=True,
         bint copy=True,

pandas/core/dtypes/cast.py

@@ -1610,7 +1610,6 @@ def construct_1d_ndarray_preserving_na(
     """
 
     if dtype is not None and dtype.kind == "U":
-        values = np.asarray(values, dtype="object")
         subarr = lib.ensure_string_array(values, convert_na_value=False, copy=copy)
     else:
         subarr = np.array(values, dtype=dtype, copy=copy)