expand '~' with path.expanduser in KVLoader

tests included

IPython/config/loader.py

@@ -19,6 +19,7 b' Authors'
 #-----------------------------------------------------------------------------
 
 import __builtin__ as builtin_mod
+import os
 import re
 import sys
 
@@ -332,6 +333,14 b' class CommandLineConfigLoader(ConfigLoader):'
     """
 
     def _exec_config_str(self, lhs, rhs):
+        """execute self.config.<lhs>=<rhs>
+        
+        * expands ~ with expanduser
+        * tries to assign with raw exec, otherwise assigns with just the string,
+          allowing `--C.a=foobar` and `--C.a="foobar"` to be equivalent.  *Not*
+          equivalent are `--C.a=4` and `--C.a='4'`.
+        """
+        rhs = os.path.expanduser(rhs)
         exec_str = 'self.config.' + lhs + '=' + rhs
         try:
             # Try to see if regular Python syntax will work. This
@@ -343,7 +352,7 b' class CommandLineConfigLoader(ConfigLoader):'
             # the quote marks. Use repr, to get quote marks, and
             # 'u' prefix and see if
             # it succeeds. If it still fails, we let it raise.
-            exec_str = u'self.config.' + lhs + '=' + repr(rhs)
+            exec_str = u'self.config.' + lhs + '= rhs'
             exec exec_str in locals(), globals()
 
     def _load_flag(self, cfg):

IPython/config/tests/test_loader.py

@@ -131,6 +131,16 b' class TestKeyValueCL(TestCase):'
         self.assertEquals(config.Foo.Bam.value, range(10))
         self.assertEquals(config.D.C.value, 'hi there')
     
+    def test_expanduser(self):
+        cl = self.klass()
+        argv = ['--a=~/1/2/3', '--b=~', '--c=~/', '--d="~/"']
+        with mute_warn():
+            config = cl.load_config(argv)
+        self.assertEquals(config.a, os.path.expanduser('~/1/2/3'))
+        self.assertEquals(config.b, os.path.expanduser('~'))
+        self.assertEquals(config.c, os.path.expanduser('~/'))
+        self.assertEquals(config.d, '~/')
+    
     def test_extra_args(self):
         cl = self.klass()
         with mute_warn():
@@ -172,6 +182,14 b' class TestKeyValueCL(TestCase):'
 class TestArgParseKVCL(TestKeyValueCL):
     klass = KVArgParseConfigLoader
 
+    def test_expanduser2(self):
+        cl = self.klass()
+        argv = ['-a', '~/1/2/3', '--b', "'~/1/2/3'"]
+        with mute_warn():
+            config = cl.load_config(argv, aliases=dict(a='A.a', b='A.b'))
+        self.assertEquals(config.A.a, os.path.expanduser('~/1/2/3'))
+        self.assertEquals(config.A.b, '~/1/2/3')
+    
 class TestConfig(TestCase):
 
     def test_setget(self):