Merge pull request #136 from jakirkham/ret_ndarray_encode_decode

Return `ndarray`s from `encode` and (where possible) `decode`

Author: alimanfoo

docs/release.rst

@@ -41,6 +41,10 @@ Release notes
   code readability and maintainability. By :user:`John Kirkham <jakirkham>` and
   :user:`Alistair Miles <alimanfoo>`; :issue:`119`, :issue:`121`, :issue:`128`.
 
+* Return values from encode() and decode() methods are now returned as numpy 
+  arrays for consistency across codecs. By :user:`John Kirkham <jakirkham>`, 
+  :issue:`136`.
+
 * Improvements to handling of errors in the :class:`numcodecs.blosc.Blosc` and 
   :class:`numcodecs.lz4.LZ4` codecs when the maximum allowed size of an input 
   buffer is exceeded. By :user:`Jerome Kelleher <jeromekelleher>`, :issue:`80`,

numcodecs/blosc.c

@@ -16,7 +16,7 @@ from cpython.bytes cimport PyBytes_FromStringAndSize, PyBytes_AS_STRING
 
 from .compat_ext cimport Buffer
 from .compat_ext import Buffer
-from .compat import PY2, text_type, ensure_contiguous_ndarray
+from .compat import PY2, text_type, ensure_ndarray, ensure_contiguous_ndarray
 from .abc import Codec
 
 
@@ -488,11 +488,13 @@ class Blosc(Codec):
 
     def encode(self, buf):
         buf = ensure_contiguous_ndarray(buf, self.max_buffer_size)
-        return compress(buf, self._cname_bytes, self.clevel, self.shuffle, self.blocksize)
+        out = compress(buf, self._cname_bytes, self.clevel, self.shuffle, self.blocksize)
+        return  ensure_ndarray(out)
 
     def decode(self, buf, out=None):
         buf = ensure_contiguous_ndarray(buf, self.max_buffer_size)
-        return decompress(buf, out)
+        out = decompress(buf, out)
+        return ensure_ndarray(out)
 
     def __repr__(self):
         r = '%s(cname=%r, clevel=%r, shuffle=%s, blocksize=%s)' % \

numcodecs/blosc.pyx

@@ -4,7 +4,7 @@
 
 
 from numcodecs.abc import Codec
-from numcodecs.compat import ndarray_copy, ensure_contiguous_ndarray
+from numcodecs.compat import ndarray_copy, ensure_ndarray, ensure_contiguous_ndarray
 
 
 class BZ2(Codec):
@@ -28,7 +28,7 @@ def encode(self, buf):
         buf = ensure_contiguous_ndarray(buf)
 
         # do compression
-        return _bz2.compress(buf, self.level)
+        return ensure_ndarray(_bz2.compress(buf, self.level))
 
     # noinspection PyMethodMayBeStatic
     def decode(self, buf, out=None):

numcodecs/bz2.py

@@ -13,7 +13,7 @@ from cpython.bytes cimport PyBytes_FromStringAndSize, PyBytes_AS_STRING
 
 from .compat_ext cimport Buffer
 from .compat_ext import Buffer
-from .compat import PY2, ensure_contiguous_ndarray
+from .compat import PY2, ensure_ndarray, ensure_contiguous_ndarray
 from .abc import Codec
 
 
@@ -219,11 +219,11 @@ class LZ4(Codec):
 
     def encode(self, buf):
         buf = ensure_contiguous_ndarray(buf, self.max_buffer_size)
-        return compress(buf, self.acceleration)
+        return ensure_ndarray(compress(buf, self.acceleration))
 
     def decode(self, buf, out=None):
         buf = ensure_contiguous_ndarray(buf, self.max_buffer_size)
-        return decompress(buf, out)
+        return ensure_ndarray(decompress(buf, out))
 
     def __repr__(self):
         r = '%s(acceleration=%r)' % \

numcodecs/lz4.c

@@ -15,7 +15,7 @@
 if _lzma:
 
     from .abc import Codec
-    from .compat import ndarray_copy, ensure_contiguous_ndarray
+    from .compat import ndarray_copy, ensure_ndarray, ensure_contiguous_ndarray
 
     # noinspection PyShadowingBuiltins
     class LZMA(Codec):
@@ -51,8 +51,8 @@ def encode(self, buf):
             buf = ensure_contiguous_ndarray(buf)
 
             # do compression
-            return _lzma.compress(buf, format=self.format, check=self.check,
-                                  preset=self.preset, filters=self.filters)
+            return ensure_ndarray(_lzma.compress(buf, format=self.format, check=self.check,
+                                                 preset=self.preset, filters=self.filters))
 
         def decode(self, buf, out=None):
 

numcodecs/lz4.pyx

@@ -13,7 +13,7 @@ import numpy as np
 from .abc import Codec
 from .compat_ext cimport Buffer
 from .compat_ext import Buffer
-from .compat import ensure_contiguous_ndarray
+from .compat import ensure_ndarray, ensure_contiguous_ndarray
 from cpython cimport (PyBytes_GET_SIZE, PyBytes_AS_STRING, PyBytes_Check,
                       PyBytes_FromStringAndSize, PyUnicode_AsUTF8String)
 from cpython.buffer cimport PyBUF_ANY_CONTIGUOUS
@@ -130,7 +130,7 @@ class VLenUTF8(Codec):
             memcpy(data, encv, l)
             data += l
 
-        return out
+        return ensure_ndarray(out)
 
     @cython.wraparound(False)
     @cython.boundscheck(False)

numcodecs/lzma.py

@@ -4,7 +4,7 @@
 
 
 from .abc import Codec
-from .compat import ndarray_copy, ensure_contiguous_ndarray
+from .compat import ndarray_copy, ensure_ndarray, ensure_contiguous_ndarray
 
 
 class Zlib(Codec):
@@ -28,7 +28,7 @@ def encode(self, buf):
         buf = ensure_contiguous_ndarray(buf)
 
         # do compression
-        return _zlib.compress(buf, self.level)
+        return ensure_ndarray(_zlib.compress(buf, self.level))
 
     # noinspection PyMethodMayBeStatic
     def decode(self, buf, out=None):