diff options
Diffstat (limited to 'numpy/ma')
| -rw-r--r-- | numpy/ma/core.py | 31 | ||||
| -rw-r--r-- | numpy/ma/tests/test_core.py | 11 |
2 files changed, 29 insertions, 13 deletions
diff --git a/numpy/ma/core.py b/numpy/ma/core.py index 9ae225728..472b04429 100644 --- a/numpy/ma/core.py +++ b/numpy/ma/core.py @@ -6184,11 +6184,11 @@ isMA = isMaskedArray # backward compatibility class MaskedConstant(MaskedArray): - + # the lone np.ma.masked instance __singleton = None - def __new__(self): - if self.__singleton is None: + def __new__(cls): + if cls.__singleton is None: # We define the masked singleton as a float for higher precedence. # Note that it can be tricky sometimes w/ type comparison data = np.array(0.) @@ -6198,10 +6198,12 @@ class MaskedConstant(MaskedArray): data.flags.writeable = False mask.flags.writeable = False - masked = MaskedArray(data, mask=mask) - self.__singleton = masked.view(self) + # don't fall back on MaskedArray.__new__(MaskedConstant), since + # that might confuse it - this way, the construction is entirely + # within our control + cls.__singleton = MaskedArray(data, mask=mask).view(cls) - return self.__singleton + return cls.__singleton def __array_finalize__(self, obj): if self.__singleton is None: @@ -6215,7 +6217,7 @@ class MaskedConstant(MaskedArray): # everywhere else, we want to downcast to MaskedArray, to prevent a # duplicate maskedconstant. self.__class__ = MaskedArray - self.__array_finalize__(obj) + MaskedArray.__array_finalize__(self, obj) def __array_prepare__(self, obj, context=None): return self.view(MaskedArray).__array_prepare__(obj, context) @@ -6227,10 +6229,10 @@ class MaskedConstant(MaskedArray): return str(masked_print_option._display) def __repr__(self): - if self is masked: + if self is self.__singleton: return 'masked' else: - # something is wrong, make it obvious + # it's a subclass, or something is wrong, make it obvious return object.__repr__(self) def __reduce__(self): @@ -6240,9 +6242,16 @@ class MaskedConstant(MaskedArray): # inplace operations have no effect. We have to override them to avoid # trying to modify the readonly data and mask arrays - def __inop(self, other): + def __iop__(self, other): return self - __iadd__ = __isub__ = __imul__ = __ifloordiv__ = __itruediv__ = __ipow__ = __inop + __iadd__ = \ + __isub__ = \ + __imul__ = \ + __ifloordiv__ = \ + __itruediv__ = \ + __ipow__ = \ + __iop__ + del __iop__ # don't leave this around masked = masked_singleton = MaskedConstant() diff --git a/numpy/ma/tests/test_core.py b/numpy/ma/tests/test_core.py index bf83461d7..69a3a0dc4 100644 --- a/numpy/ma/tests/test_core.py +++ b/numpy/ma/tests/test_core.py @@ -4762,9 +4762,16 @@ class TestMaskedConstant(TestCase): assert_equal(np.ma.masked.mask, True) def test_no_copies(self): + # when making a view or a copy, downcast to MaskedArray MC = np.ma.core.MaskedConstant - assert_(not isinstance(np.ma.masked[...], MC)) - assert_(not isinstance(np.ma.masked.copy(), MC)) + + m_sl = np.ma.masked[...] + assert_equal(type(m_sl), np.ma.MaskedArray) + assert_equal(m_sl.mask, True) + + m_copy = np.ma.masked.copy() + assert_equal(type(m_copy), np.ma.MaskedArray) + # assert_equal(m_copy.mask, True) - gh-9430 def test_immutable(self): assert_raises(ValueError, operator.setitem, np.ma.masked.data, (), 1) |