Added docstring.

theano/tensor/utils.py

@@ -4,6 +4,11 @@ from theano.gof.cc import hash_from_code
 
 
 def hash_from_ndarray(data):
+    """Return a hash from an ndarray
+
+    It take care of the data, shapes, strides and dtype.
+
+    """
     # We need to hash the shapes and strides as hash_from_code only hashes
     # the data buffer. Otherwise, this will cause problem with shapes like:
     # (1, 0) and (2, 0) and problem with inplace transpose.