ENH: Apply masks (#36)

Author: TomAugspurger

cyberpandas/ip_array.py

@@ -148,6 +148,11 @@ def _from_ndarray(cls, data, copy=False):
         new.data = data
         return new
 
+    @property
+    def _as_u8(self):
+        """A 2-D view on our underlying data, for bit-level manipulation."""
+        return self.data.view("<u8").reshape(-1, 1)
+
     # -------------------------------------------------------------------------
     # Properties
     # -------------------------------------------------------------------------
@@ -607,6 +612,38 @@ def hostmask(self, v4_prefixlen=32, v6_prefixlen=128):
         """
         return self._apply_mask('hostmask', v4_prefixlen, v6_prefixlen)
 
+    def mask(self, mask):
+        """Apply a host or subnet mask.
+
+        Parameters
+        ----------
+        mask : IPArray
+            The host or subnet mask to be applied
+
+        Returns
+        -------
+        masked : IPArray
+
+        See Also
+        --------
+        netmask
+        hostmask
+
+        Examples
+        --------
+        >>> arr = IPArray(['216.003.128.12', '192.168.100.1'])
+        >>> mask = arr.netmask(v4_prefixlen=24)
+        >>> mask
+        IPArray(['255.255.255.0', '255.255.255.0'])
+        >>> arr.mask(mask)
+        IPArray(['216.3.128.0', '192.168.100.0'])
+        """
+        mask = type(self)(mask)
+        a = self._as_u8
+        b = mask._as_u8
+        masked = np.bitwise_and(a, b).ravel().view(self.dtype._record_type)
+        return type(self)(masked)
+
 
 # -----------------------------------------------------------------------------
 # Accessor
@@ -653,6 +690,10 @@ def hostmask(self, v4_prefixlen=32, v6_prefixlen=128):
         return delegated_method(self._data.hostmask, self._index,
                                 self._name, v4_prefixlen, v6_prefixlen)
 
+    def mask(self, other):
+        return delegated_method(self._data.mask, self._index, self._name,
+                                other)
+
 
 def is_ipaddress_type(obj):
     t = getattr(obj, 'dtype', obj)

docs/source/api.rst

@@ -43,7 +43,6 @@ an IPArray, calling the Series method will dispatch to these methods.
 .. automethod:: IPArray.unique
 .. automethod:: IPArray.isin
 .. automethod:: IPArray.isna
-.. autoattribute:: IPArray.netmask
 
 IP Address Attributes
 """""""""""""""""""""
@@ -62,6 +61,7 @@ IP addresss-specific attributes.
 .. autoattribute:: IPArray.is_link_local
 .. automethod:: IPArray.netmask
 .. automethod:: IPArray.hostmask
+.. automethod:: IPArray.mask
 
 
 

docs/source/changelog.rst

@@ -2,6 +2,12 @@
 Changelog
 #########
 
+*************
+Version 1.1.1
+*************
+
+- Added :meth:`IPArray.mask` to apply net and host masks to an array of IP addresses (:issue:`36`).
+
 *************
 Version 1.1.0
 *************

tests/ip/test_ip.py

@@ -382,3 +382,15 @@ def test_hostmask_basic():
                                                     v6_prefixlen=32)
     assert result.name == 'foo'
     assert result.values.equals(expected)
+
+
+def test_apply_mask():
+    arr = ip.IPArray([u'216.3.128.0', u'192.168.100.0', u'1::1:12'])
+    mask = arr.netmask(v4_prefixlen=24, v6_prefixlen=112)
+    result = arr.mask(mask)
+    expected = ip.IPArray([u'216.3.128.0', u'192.168.100.0', u'1::1:0'])
+    assert result.equals(expected)
+
+    result = pd.Series(arr, name='test').ip.mask(mask)
+    expected = pd.Series(expected, name='test')
+    tm.assert_series_equal(result, expected)