Ensure window_indexer.pyx gets compiled by cython

pandas/_libs/window_indexer.pyx

@@ -2,14 +2,13 @@
 
 import numpy as np
 from numpy cimport ndarray, int64_t
-cnp.import_array()
 
 # ----------------------------------------------------------------------
 # The indexer objects for rolling
 # These define start/end indexers to compute offsets
 
 
-cpdef class MockFixedWindowIndexer:
+class MockFixedWindowIndexer:
     """
 
     We are just checking parameters of the indexer,
@@ -36,7 +35,7 @@ cpdef class MockFixedWindowIndexer:
         return self.start, self.end
 
 
-cpdef class FixedWindowIndexer:
+class FixedWindowIndexer:
     """
     create a fixed length window indexer object
     that has start & end, that point to offsets in
@@ -70,7 +69,7 @@ cpdef class FixedWindowIndexer:
     def get_window_bounds(self):
         return self.start, self.end
 
-cpdef class VariableWindowIndexer:
+class VariableWindowIndexer:
     """
     create a variable length window indexer object
     that has start & end, that point to offsets in
@@ -115,7 +114,7 @@ cpdef class VariableWindowIndexer:
 
         cdef:
             ndarray[int64_t] start, end
-            int64_t start_bound, end_bound, N
+            int64_t start_bound, end_bound
             Py_ssize_t i, j
 
         start = np.empty(N, dtype='int64')

pandas/core/window/rolling.py

@@ -46,9 +46,7 @@
     _flex_binary_moment,
     _GroupByMixin,
     _offset,
-    _require_min_periods,
     _shared_docs,
-    _use_window,
     _zsqrt,
 )
 

setup.py

@@ -348,6 +348,7 @@ class CheckSDist(sdist_class):
         "pandas/_libs/tslibs/resolution.pyx",
         "pandas/_libs/tslibs/parsing.pyx",
         "pandas/_libs/tslibs/tzconversion.pyx",
+        "pandas/_libs/window_indexer.pyx",
         "pandas/_libs/writers.pyx",
         "pandas/io/sas/sas.pyx",
     ]
@@ -687,6 +688,7 @@ def srcpath(name=None, suffix=".pyx", subdir="src"):
     },
     "_libs.testing": {"pyxfile": "_libs/testing"},
     "_libs.window": {"pyxfile": "_libs/window", "language": "c++", "suffix": ".cpp"},
+    "_libs.window_indexer": {"pyxfile": "_libs/window_indexer"},
     "_libs.writers": {"pyxfile": "_libs/writers"},
     "io.sas._sas": {"pyxfile": "io/sas/sas"},
     "io.msgpack._packer": {