ENH: core: Generalize ndarray.astype to take new standard keyword arguments

These include order=, casting=, subok=. Also added a forcecopy=
parameter to allow skipping of the copy when possible.

1 files changed, 26 insertions, 2 deletions

diff --git a/numpy/add_newdocs.py b/numpy/add_newdocs.py
index 37f326867..e596607fa 100644
--- a/numpy/add_newdocs.py
+++ b/numpy/add_newdocs.py
@@ -3001,14 +3001,38 @@ add_newdoc('numpy.core.multiarray', 'ndarray', ('argsort',
 
 add_newdoc('numpy.core.multiarray', 'ndarray', ('astype',
     """
-    a.astype(t)
+    a.astype(dtype, order='K', casting='unsafe', subok=True, forcecopy=True)
 
     Copy of the array, cast to a specified type.
 
     Parameters
     ----------
-    t : str or dtype
+    dtype : str or dtype
         Typecode or data-type to which the array is cast.
+    order : {'C', 'F', 'A', or 'K'}, optional
+        Controls the memory layout order of the result.
+        'C' means C order, 'F' means Fortran order, 'A'
+        means 'F' order if all the arrays are Fortran contiguous,
+        'C' order otherwise, and 'K' means as close to the
+        order the array elements appear in memory as possible.
+        Default is 'K'.
+    casting : {'no', 'equiv', 'safe', 'same_kind', 'unsafe'}, optional
+        Controls what kind of data casting may occur. Defaults to 'unsafe'
+        for backwards compatibility.
+
+          * 'no' means the data types should not be cast at all.
+          * 'equiv' means only byte-order changes are allowed.
+          * 'safe' means only casts which can preserve values are allowed.
+          * 'same_kind' means only safe casts or casts within a kind,
+            like float64 to float32, are allowed.
+          * 'unsafe' means any data conversions may be done.
+    subok : bool, optional
+        If True, then sub-classes will be passed-through (default), otherwise
+        the returned array will be forced to be a base-class array.
+    forcecopy : bool, optional
+        By default, astype always returns a new array. If this is set to
+        false, and the `dtype`, `order`, and `subok` requirements are
+        satisfied, the input array is returned instead of a copy.
 
     Raises
     ------