Re-use common constructor test

python/pyarrow/memory.pxi

@@ -23,7 +23,8 @@
 cdef class MemoryPool:
 
     def __init__(self):
-        raise TypeError("Do not call {}'s constructor directly"
+        raise TypeError("Do not call {}'s constructor directly, "
+                        "use pyarrow.*_memory_pool instead."
                         .format(self.__class__.__name__))
 
     cdef void init(self, CMemoryPool* pool):
@@ -60,13 +61,10 @@ cdef class LoggingMemoryPool(MemoryPool):
         unique_ptr[CLoggingMemoryPool] logging_pool
 
     def __init__(self):
-        raise TypeError("Do not call {}'s constructor directly"
+        raise TypeError("Do not call {}'s constructor directly, "
+                        "use pyarrow.logging_memory_pool instead."
                         .format(self.__class__.__name__))
 
-    def __cinit__(self, MemoryPool pool):
-        self.logging_pool.reset(new CLoggingMemoryPool(pool.pool))
-        self.init(self.logging_pool.get())
-
 
 cdef class ProxyMemoryPool(MemoryPool):
     """
@@ -77,8 +75,8 @@ cdef class ProxyMemoryPool(MemoryPool):
         unique_ptr[CProxyMemoryPool] proxy_pool
 
     def __init__(self):
-        raise TypeError("Do not call {}'s constructor directly. "
-                        "Use pyarrow.proxy_memory_pool instead."
+        raise TypeError("Do not call {}'s constructor directly, "
+                        "use pyarrow.proxy_memory_pool instead."
                         .format(self.__class__.__name__))
 
 
@@ -105,7 +103,11 @@ def logging_memory_pool(MemoryPool parent):
     Create and return a MemoryPool instance that redirects to the
     *parent*, but also dumps allocation logs on stderr.
     """
-    return LoggingMemoryPool.__new__(LoggingMemoryPool, parent)
+    cdef LoggingMemoryPool out = LoggingMemoryPool.__new__(
+        LoggingMemoryPool, parent)
+    out.logging_pool.reset(new CLoggingMemoryPool(parent.pool))
+    out.init(out.logging_pool.get())
+    return out
 
 
 def set_memory_pool(MemoryPool pool):

python/pyarrow/tests/test_memory.py

@@ -17,8 +17,6 @@
 
 import contextlib
 
-import pytest
-
 import pyarrow as pa
 
 
@@ -53,17 +51,6 @@ def check_allocated_bytes(pool):
     assert pool.max_memory() == new_max_memory
 
 
-def test_cannot_use_constructors():
-    with pytest.raises(TypeError):
-        pa.MemoryPool()
-
-    with pytest.raises(TypeError):
-        pa.ProxyMemoryPool()
-
-    with pytest.raises(TypeError):
-        pa.LoggingMemoryPool()
-
-
 def test_default_allocated_bytes():
     pool = pa.default_memory_pool()
     with allocate_bytes(pool, 1024):

python/pyarrow/tests/test_misc.py

@@ -117,7 +117,10 @@ def test_cpu_count():
     pa.StructValue,
     pa.DictionaryValue,
     pa.ipc.Message,
-    pa.ipc.MessageReader
+    pa.ipc.MessageReader,
+    pa.MemoryPool,
+    pa.LoggingMemoryPool,
+    pa.ProxyMemoryPool,
 ])
 def test_extension_type_constructor_errors(klass):
     # ARROW-2638: prevent calling extension class constructors directly