Config singleton class

kepi/config.py

@@ -0,0 +1,50 @@
+import argparse
+
+class Config:
+
+    settings = {}
+    subcommands = []
+    argparser = None
+
+    def __init__(self):
+        raise NotImplementedError()
+
+    def users(self):
+        raise ValueError()
+
+    def __getattr__(self, field):
+        if field in self.settings:
+            return self.settings[field]
+        else:
+            raise KeyError(field)
+
+    def parse_args(self, argparser):
+
+        assert self.subcommands is not None
+
+        self.argparser = argparser
+
+        self.subparsers = argparser.add_subparsers(
+                dest = 'command',
+                required = True,
+                )
+
+        for sub in self.subcommands:
+            sub(self.subparsers)
+
+        self.subcommands = None
+
+        args = self.argparser.parse_args()
+
+        for field in dir(args):
+            if field.startswith('_'):
+                continue
+            self.settings[field] = getattr(args, field)
+
+        # TODO here we will check the config file, and merge them in.
+
+config = Config.__new__(Config)
+
+def subcommand(fn):
+    config.subcommands.append(fn)
+    return None