FEAT: allow ; in __getitem__ and __setitem__ (closes larray-project#904)

so that we can target multiple axes in a single string. eg. arr['a1;b1'] or arr['b1..b3;a2,a1']

Author: gdementen

doc/source/changes/version_0_34.rst.inc

@@ -18,6 +18,17 @@ Backward incompatible changes
 New features
 ^^^^^^^^^^^^
 
+* allow ";" in __getitem__ and __setitem__ strings, making it possible to specify keys for several axes in a single
+  string (closes :issue:`904`). For example:
+
+    >>> arr = ndtest((2, 3))
+    >>> arr
+    a\b  b0  b1  b2
+     a0   0   1   2
+     a1   3   4   5
+    >>> arr['a1;b2']
+    5
+
 * added a feature (see the :ref:`miscellaneous section <misc>` for details). It works on :ref:`api-axis` and
   :ref:`api-group` objects.
 

larray/core/axis.py

@@ -2811,6 +2811,12 @@ def _key_to_axis_indices_dict(self, key):
         """
         from .array import Array
 
+        if isinstance(key, str) and ';' in key:
+            # FIXME: it would be more logical to use _to_keys(key) instead but this breaks
+            # the "target an aggregate with its key" feature (test_getitem_on_group_agg).
+            # It might be a good thing though as it costs so much for so little use.
+            # key = _to_keys(key)
+            key = tuple(key.split(';'))
         if isinstance(key, dict):
             # key axes could be strings or axis references and we want real axes
             key = tuple(self[axis][axis_key] for axis, axis_key in key.items())

larray/tests/test_array.py

@@ -651,6 +651,14 @@ def test_getitem_guess_axis(array):
     res = arr['b[l1]']
     assert_array_equal(res, arr.data[:, 0])
 
+    # several axes in same string (guess axis)
+    res = arr['l0;l2']
+    assert res == 1
+
+    # several axes in same string (with axis information)
+    res = arr['a[l1];b[l2]']
+    assert res == 3
+
 
 def test_getitem_positional_group(array):
     raw = array.data