fix #671 : implemented 'integerstring[labels]' and 'integerstring.i[indices]'

Author: alixdamman

doc/source/changes/version_0_30.rst.inc

@@ -153,6 +153,26 @@ Miscellaneous improvements
 
   Closes :issue:`669`.
 
+* allowed to specify an axis by its postion when selecting a subset of an array using the string notation:
+
+    >>> pop_mouv = ndtest('geo_from=BE,FR,UK;geo_to=BE,FR,UK')
+    >>> pop_mouv
+    geo_from\geo_to  BE  FR  UK
+                 BE   0   1   2
+                 FR   3   4   5
+                 UK   6   7   8
+    >>> pop_mouv['0[BE, UK]']   # equivalent to pop_mouv[pop_mouv.geo_from['BE,UK']]
+    geo_from\geo_to  BE  FR  UK
+                 BE   0   1   2
+                 UK   6   7   8
+    >>> pop_mouv['1.i[0, 2]']   # equivalent to pop_mouv[pop_mouv.geo_to.i[0, 2]]
+    geo_from\geo_to  BE  UK
+                 BE   0   2
+                 FR   3   5
+                 UK   6   8
+
+  Closes :issue:`671`.
+
 
 Fixes
 -----

larray/core/axis.py

@@ -2318,6 +2318,14 @@ def _translate_axis_key(self, axis_key, bool_passthrough=True):
         """
         from .array import LArray
 
+        # Need to convert string keys to groups otherwise command like
+        # >>> ndtest((5, 5)).drop('1[a0]')
+        # will work although it shouldn't
+        if isinstance(axis_key, basestring):
+            key = _to_key(axis_key)
+            if isinstance(key, Group):
+                axis_key = key
+
         if isinstance(axis_key, ExprNode):
             raise Exception('yada')
             axis_key = axis_key.evaluate(self)

larray/core/group.py

@@ -12,7 +12,7 @@
 
 from larray.core.abstractbases import ABCAxis, ABCAxisReference, ABCLArray
 from larray.util.oset import *
-from larray.util.misc import (basestring, PY2, unique, find_closing_chr, _parse_bound, _seq_summary,
+from larray.util.misc import (basestring, PY2, unique, find_closing_chr, _parse_bound, _seq_summary, _isintstring,
                               renamed_to, LHDFStore)
 
 _deprecated = ['PGroup']
@@ -439,7 +439,7 @@ def _to_ticks(s, parse_single_int=False):
     return np.asarray(ticks)
 
 
-_axis_name_pattern = re.compile('\s*(([A-Za-z]\w*)(\.i)?\s*\[)?(.*)')
+_axis_name_pattern = re.compile('\s*(([A-Za-z0-9]\w*)(\.i)?\s*\[)?(.*)')
 
 
 def _seq_str_to_seq(s, stack_depth=1, parse_single_int=False):
@@ -530,6 +530,10 @@ def _to_key(v, stack_depth=1, parse_single_int=False):
     LGroup(['a', 'b', 'c']) >> 'abc'
     >>> _to_key('a:c >> abc')
     LGroup(slice('a', 'c', None)) >> 'abc'
+    >>> _to_key('0[a0]')
+    0['a0']
+    >>> _to_key('0.i[a0]')
+    0.i['a0']
 
     # evaluated variables do not work on Python 2, probably because the stackdepth is different
     # >>> ext = [1, 2, 3]
@@ -564,6 +568,8 @@ def _to_key(v, stack_depth=1, parse_single_int=False):
             key, name = key[:name_pos].strip(), key[name_pos + 2:].strip()
         if axis is not None:
             axis = axis.strip()
+            if _isintstring(axis):
+                axis = int(axis)
             axis_bracket_open = m.end(1) - 1
             # check that the string parentheses are correctly balanced
             _ = find_closing_chr(v, axis_bracket_open)

larray/tests/test_array.py

@@ -658,6 +658,21 @@ def test_getitem_igroup_on_int_axis():
     assert arr[a.i[1]] == 1
 
 
+def test_getitem_integer_string_axes():
+    arr = ndtest((5, 5))
+    a, b = arr.axes
+
+    assert_array_equal(arr['0[a0, a2]'], arr[a['a0', 'a2']])
+    assert_array_equal(arr['0[a0:a2]'], arr[a['a0:a2']])
+    with pytest.raises(ValueError):
+        arr['1[a0, a2]']
+
+    assert_array_equal(arr['0.i[0, 2]'], arr[a.i[0, 2]])
+    assert_array_equal(arr['0.i[0:2]'], arr[a.i[0:2]])
+    with pytest.raises(ValueError):
+        arr['3.i[0, 2]']
+
+
 def test_getitem_int_larray_lgroup_key():
     # e axis go from 0 to 3
     arr = ndtest("c=0,1; d=0,1; e=0..3")