Fix the file API

handel/interface.py

@@ -46,8 +46,8 @@ def to_buffer_id(bid):
 
 # Initializing handel
 
-def init(filename):
-    filename = to_bytes(filename)
+def init(*path):
+    filename = to_bytes(os.path.join(*path))
     code = handel.xiaInit(filename)
     check_error(code)
 
@@ -172,14 +172,14 @@ def buffer_done(channel, buffer_id):
 
 # System
 
-def load_system(filename):
-    filename = to_bytes(filename)
+def load_system(*path):
+    filename = to_bytes(os.path.join(*path))
     code = handel.xiaLoadSystem(b'handel_ini', filename)
     check_error(code)
 
 
-def save_system(filename):
-    filename = to_bytes(filename)
+def save_system(*path):
+    filename = to_bytes(os.path.join(*path))
     code = handel.xiaSaveSystem(b'handel_ini', filename)
     check_error(code)
 
@@ -409,7 +409,8 @@ def get_handel_version():
 def get_config_files(path):
     """Return all the ini files in path (including subdirectories)."""
     ext = b'.ini' if isinstance(path, bytes) else '.ini'
-    return [os.path.join(dp, f).lstrip(path).lstrip('/')
+    sep = b'/' if isinstance(path, bytes) else '/'
+    return [os.path.join(dp, f).lstrip(path).lstrip(sep)
             for dp, dn, fn in os.walk(path)
             for f in fn
             if f.endswith(ext)]