Add an init method to the module that do all the hard work.

This is for simplifying the usage and allowing access to some elements
(like the initial configuration or and ``CommandLine`` object) from plugins.

This `init` method initialize the ``CommandLine`` object, parse the
arguments and set the configuration and the initialized instance to the module
namespace.

It takes five parameters:

    * `format`: format of the configuration (*yaml*, *json* or *raw*),
    * `data`: a filepath for *yaml* and *json* format and a dictionnary
      for *raw* format,
    * `completion`: allows to initialize argcomplete for bash/zsh
      completion,
    * `subcommands_keyword`: *keyword* parameter of the ``CommandLine``
      object,
    * `deepcopy`: *deepcopy* parameter of the ``CommandLine`` object

By default, the configuration is loaded from the YAML file *cmd.yml* on
the program directory.

clg/__init__.py

@@ -1,4 +1,4 @@
-# -*- coding: utf-8 -*-
+# coding: utf-8
 
 """This module is a wrapper to ``argparse`` module. It allow to generate a
 command-line from a predefined directory (ie: a YAML, JSON, ... file)."""
@@ -742,3 +742,43 @@ def print_line(cmd, line, first_line, has_childs):
         else:
             print(output)
         sys.exit(0)
+
+
+def init(format='yaml', data=os.path.join(sys.path[0], 'cmd.yml'),
+         completion=False, subcommands_keyword='command', deepcopy=True):
+    """Wrapping method that initialize the command-line and export the input
+    configuration and the **CommandLine** object at the module level.
+
+    The configuration is loaded based on the format `format` and `data`. `data`
+    is a filepath if `format` is *yaml* or *json* and a dictionnary if `format`
+    is *raw*. By default, the configuration is loaded from the file *cmd.yml* in
+    the program directory.
+
+    `completion` parameter allows to initialize ``argcomplete`` for completion.
+    """
+    # Get command-line configuration based on format and data and initialize CommandLine.
+    if format == 'yaml':
+        import yaml, yamlordereddictloader
+        config = yaml.load(open(data), Loader=yamlordereddictloader.Loader)
+    elif format == 'json':
+        import json
+        config = json.load(open('cmd.json'), object_pairs_hook=OrderedDict)
+    elif format == 'raw':
+        config = data
+    else:
+        raise CLGError('unsupported format: %s' % format)
+    cmd = CommandLine(config, subcommands_keyword, deepcopy)
+
+    # Activate completion if wished.
+    if completion:
+        import argcomplete
+        argcomplete.autocomplete(cmd.parser)
+
+    # Set attributes to the module itself.
+    setattr(_SELF, 'config', config)
+    setattr(_SELF, 'cmd', cmd)
+
+    # Parse arguments.
+    args = cmd.parse()
+
+    return args