[pypy-commit] pypy default: Add issubdtype

[rguillebert]

Author: Romain Guillebert <romain.py at gmail.com>
Branch: 
Changeset: r67218:8f6cfebce395
Date: 2013-10-08 17:06 +0200
http://bitbucket.org/pypy/pypy/changeset/8f6cfebce395/

Log:	Add issubdtype

diff --git a/lib_pypy/numpypy/core/numerictypes.py b/lib_pypy/numpypy/core/numerictypes.py
--- a/lib_pypy/numpypy/core/numerictypes.py
+++ b/lib_pypy/numpypy/core/numerictypes.py
@@ -1,1 +1,75 @@
 from _numpypy.numerictypes import *
+import numpypy
+
+def issubclass_(arg1, arg2):
+    """
+    Determine if a class is a subclass of a second class.
+
+    `issubclass_` is equivalent to the Python built-in ``issubclass``,
+    except that it returns False instead of raising a TypeError is one
+    of the arguments is not a class.
+
+    Parameters
+    ----------
+    arg1 : class
+        Input class. True is returned if `arg1` is a subclass of `arg2`.
+    arg2 : class or tuple of classes.
+        Input class. If a tuple of classes, True is returned if `arg1` is a
+        subclass of any of the tuple elements.
+
+    Returns
+    -------
+    out : bool
+        Whether `arg1` is a subclass of `arg2` or not.
+
+    See Also
+    --------
+    issubsctype, issubdtype, issctype
+
+    Examples
+    --------
+    >>> np.issubclass_(np.int32, np.int)
+    True
+    >>> np.issubclass_(np.int32, np.float)
+    False
+
+    """
+    try:
+        return issubclass(arg1, arg2)
+    except TypeError:
+        return False
+
+def issubdtype(arg1, arg2):
+    """
+    Returns True if first argument is a typecode lower/equal in type hierarchy.
+
+    Parameters
+    ----------
+    arg1, arg2 : dtype_like
+        dtype or string representing a typecode.
+
+    Returns
+    -------
+    out : bool
+
+    See Also
+    --------
+    issubsctype, issubclass_
+    numpy.core.numerictypes : Overview of numpy type hierarchy.
+
+    Examples
+    --------
+    >>> np.issubdtype('S1', str)
+    True
+    >>> np.issubdtype(np.float64, np.float32)
+    False
+
+    """
+    if issubclass_(arg2, generic):
+        return issubclass(numpypy.dtype(arg1).type, arg2)
+    mro = numpypy.dtype(arg2).type.mro()
+    if len(mro) > 1:
+        val = mro[1]
+    else:
+        val = mro[0]
+    return issubclass(numpypy.dtype(arg1).type, val)