implemented Axis.apply

Author: gdementen

doc/source/api.rst

@@ -64,6 +64,7 @@ Modifying/Selecting
    Axis.extend
    Axis.insert
    Axis.replace
+   Axis.apply
    Axis.union
    Axis.intersection
    Axis.difference

doc/source/changes/version_0_30.rst.inc

@@ -1,4 +1,4 @@
-Syntax changes
+Syntax changes
 --------------
 
 * new syntax
@@ -96,7 +96,12 @@ New features
 * added a feature (see the :ref:`miscellaneous section <misc>` for details).
 
 
-.. _misc:
+* implemented :py:obj:`Axis.apply()` method to transform an axis labels by a function and return a new Axis.
+
+    >>> sex = Axis('sex=MALE,FEMALE')
+    >>> sex.apply(str.capitalize)
+    Axis(['Male', 'Female'], 'sex')
+
 
 Miscellaneous improvements
 --------------------------

larray/core/axis.py

@@ -1055,6 +1055,28 @@ def replace(self, old, new=None):
         labels[indices] = new
         return Axis(labels, self.name)
 
+    def apply(self, func):
+        """
+        Returns a new axis with the labels transformed by func.
+
+        Parameters
+        ----------
+        func : callable
+            A callable which takes a single argument and returns a single value.
+
+        Returns
+        -------
+        Axis
+            a new Axis with the transformed labels.
+
+        Examples
+        --------
+        >>> sex = Axis('sex=MALE,FEMALE')
+        >>> sex.apply(str.capitalize)
+        Axis(['Male', 'Female'], 'sex')
+        """
+        return Axis(map(func, self.labels), self.name)
+
     # XXX: rename to named like Group?
     def rename(self, name):
         """