THEANORC supports multiple ":"-delimited theanorc files

doc/library/config.txt

@@ -54,8 +54,8 @@ Environment Variables
 
 .. envvar:: THEANORC
 
-    This is the location of the .theanorc file which is in ConfigParser
-    format.  It defaults to ``$HOME/.theanorc``. 
+    The location[s] of the .theanorc file[s] in ConfigParser format.
+    It defaults to ``$HOME/.theanorc``. 
     
     Here is the .theanorc equivalent to the THEANO_FLAGS in the example above:
 
@@ -68,6 +68,13 @@ Environment Variables
         [nvcc]
         fastmath = True
 
+    Multiple configuration files can be specified by separating them with ':'
+    characters (as in $PATH).  Multiple configuration files will be merged,
+    with earlier (left-most) files taking priority over later files in the
+    case that multiple files specify values for a common configuration option.
+    For example, to override system-wide settings with personal ones, 
+    set ``THEANORC=~/.theanorc:/etc/theanorc``
+
 The rest of this page describes some of the more common and important flags
 that you might want to use.  For the complete list (including documentation),
 import theano and print the config variable, as in:

theano/configparser.py

@@ -14,9 +14,14 @@ THEANO_FLAGS=os.getenv("THEANO_FLAGS","")
 # [section.]option[=value] entries. If the section part is omited, their should be only one
 # section with that contain the gived option.
 
-theano_cfg_path = os.getenv('THEANORC', '~/.theanorc')
+# THEANORC=~/.theanorc:~lisa/.theanorc
+def config_files_from_theanorc():
+    rval = [os.path.expanduser(s) for s in os.getenv('THEANORC', '~/.theanorc').split(':')]
+    rval.reverse()
+    print "THEANORC", rval
+    return rval
 theano_cfg = ConfigParser.SafeConfigParser()
-theano_cfg.read([os.path.expanduser(theano_cfg_path)])
+theano_cfg.read(config_files_from_theanorc())
 
 def parse_env_flags(flags, name , default_value=None):
     #The value in the env variable THEANO_FLAGS override the previous value