Allow one-character Param names

This is done explicitly to support the l/localityname attribute.

ipalib/base.py

@@ -216,7 +216,7 @@ def check_name(name):
     >>> check_name('MyName')
     Traceback (most recent call last):
       ...
-    ValueError: name must match '^[a-z][_a-z0-9]*[a-z0-9]$'; got 'MyName'
+    ValueError: name must match '^[a-z][_a-z0-9]*[a-z0-9]$|^[a-z]$'; got 'MyName'
 
     Also, this function will raise a ``TypeError`` if ``name`` is not an
     ``str`` instance.  For example:

ipalib/config.py

@@ -74,11 +74,11 @@ class Env(object):
     >>> env.BadName = 'Wont work as an attribute'
     Traceback (most recent call last):
       ...
-    ValueError: name must match '^[a-z][_a-z0-9]*[a-z0-9]$'; got 'BadName'
+    ValueError: name must match '^[a-z][_a-z0-9]*[a-z0-9]$|^[a-z]$'; got 'BadName'
     >>> env['BadName'] = 'Also wont work as a dictionary item'
     Traceback (most recent call last):
       ...
-    ValueError: name must match '^[a-z][_a-z0-9]*[a-z0-9]$'; got 'BadName'
+    ValueError: name must match '^[a-z][_a-z0-9]*[a-z0-9]$|^[a-z]$'; got 'BadName'
 
     The variable values can be ``str``, ``int``, or ``float`` instances, or the
     ``True``, ``False``, or ``None`` constants.  When the value provided is an

ipalib/constants.py

@@ -26,7 +26,7 @@ All constants centralised in one file.
 NULLS = (None, '', u'', tuple(), [])
 
 # regular expression NameSpace member names must match:
-NAME_REGEX = r'^[a-z][_a-z0-9]*[a-z0-9]$'
+NAME_REGEX = r'^[a-z][_a-z0-9]*[a-z0-9]$|^[a-z]$'
 
 # Format for ValueError raised when name does not match above regex:
 NAME_ERROR = 'name must match %r; got %r'

ipalib/parameters.py

@@ -192,10 +192,6 @@ def parse_param_spec(spec):
         raise TypeError(
             TYPE_ERROR % ('spec', str, spec, type(spec))
         )
-    if len(spec) < 2:
-        raise ValueError(
-            'spec must be at least 2 characters; got %r' % spec
-        )
     _map = {
         '?': dict(required=False, multivalue=False),
         '*': dict(required=False, multivalue=True),

tests/test_ipalib/test_parameters.py

@@ -134,10 +134,6 @@ def test_parse_param_spec():
     e = raises(TypeError, f, u'name?')
     assert str(e) == TYPE_ERROR % ('spec', str, u'name?', unicode)
 
-    # Test that ValueError is raised if len(spec) < 2:
-    e = raises(ValueError, f, 'n')
-    assert str(e) == "spec must be at least 2 characters; got 'n'"
-
 
 class DummyRule(object):
     def __init__(self, error=None):