Merge pull request #239 in LCL/wolframclientforpython from bugfix/394303-dates to master

* commit 'd89815f7cea821cc5953364f9e18b7e9c2104590':
  adding more tests for shape and len
  adding test for generators
  array might have been a generator
  adding binary_deserialize load
  PackedArray must do the same
  _valid_type_or_fail now returns type
  code refactor
  using force_bytes for py2 compatibility
  using pack ability to serialiaze multiple values at once
  code refactor
  NumericArray is supposed to be initialized by a list of python numbers
  adding PackedArray benchmarks
  avoiding attribute lookup for every single element in the array
  speed optimizations in wxf serializer and zlib encoder

Author: crazyeng

wolframclient/language/array.py

@@ -1,6 +1,8 @@
 from __future__ import absolute_import, print_function, unicode_literals
 
 import struct
+from functools import reduce
+from operator import mul
 
 from wolframclient.exception import WolframLanguageException
 from wolframclient.serializers.wxfencoder import constants
@@ -12,6 +14,10 @@
     from collections import Sequence
 
 
+def pack(format, *elements):
+    return struct.pack(b"<%i%s" % (len(elements), force_bytes(format)), *elements)
+
+
 class NumericArray(Sequence):
     def __init__(self, array, type, shape=None):
 
@@ -29,15 +35,14 @@ def _valid_type_or_fail(self, type):
         return type
 
     def tobytes(self):
-        return struct.pack(
-            b"<%i%s" % (len(self), force_bytes(self.struct.format[1])), *self.array
-        )
+        return pack(self.struct.format[1], *self.array)
+
 
     def __getitem__(self, k):
         return self.array[k]
 
     def __len__(self):
-        return len(self.array)
+        return reduce(mul, self.shape, 1)
 
 
 class PackedArray(NumericArray):

wolframclient/tests/serializers/wxf_pythonarray.py

@@ -30,3 +30,23 @@ def test_python_array(self):
                     export(arr, target_format="wxf"),
                     export(NumericArray(array, wl_type, shape=shape), target_format="wxf"),
                 )
+
+    def test_generators(self):
+
+        array = NumericArray((i for i in range(10)), "Integer8", shape=(10, ))
+
+        self.assertEqual(
+            export(numpy.arange(10).astype(numpy.int8), target_format="wxf"),
+            export(array, target_format="wxf"),
+        )
+
+        self.assertEqual(len(array), 10)
+
+        array = NumericArray((i for i in range(10)), "Integer8", shape=(5, 2))
+
+        self.assertEqual(
+            export(numpy.arange(10).astype(numpy.int8).reshape(5, 2), target_format="wxf"),
+            export(array, target_format="wxf"),
+        )
+
+        self.assertEqual(len(array), 10)