extracted few things from lib.py

pype/lib/hooks.py

@@ -0,0 +1,71 @@
+# -*- coding: utf-8 -*-
+"""Package containing code for handling hooks."""
+import os
+import sys
+import types
+import logging
+from abc import ABCMeta, abstractmethod
+
+import six
+
+
+log = logging.getLogger(__name__)
+
+
+@six.add_metaclass(ABCMeta)
+class PypeHook:
+    """Abstract class from all hooks should inherit."""
+
+    def __init__(self):
+        """Constructor."""
+        pass
+
+    @abstractmethod
+    def execute(self, *args, **kwargs):
+        """Abstract execute method."""
+        pass
+
+
+def execute_hook(hook, *args, **kwargs):
+    """Execute hook with arguments.
+
+    This will load hook file, instantiate class and call
+    :meth:`PypeHook.execute` method on it. Hook must be in a form::
+
+        $PYPE_SETUP_PATH/repos/pype/path/to/hook.py/HookClass
+
+    This will load `hook.py`, instantiate HookClass and then execute_hook
+    `execute(*args, **kwargs)`
+
+    Args:
+        hook (str): path to hook class.
+
+    """
+    class_name = hook.split("/")[-1]
+
+    abspath = os.path.join(os.getenv('PYPE_SETUP_PATH'),
+                           'repos', 'pype', *hook.split("/")[:-1])
+
+    mod_name, mod_ext = os.path.splitext(os.path.basename(abspath))
+
+    if not mod_ext == ".py":
+        return False
+
+    module = types.ModuleType(mod_name)
+    module.__file__ = abspath
+
+    try:
+        with open(abspath) as f:
+            six.exec_(f.read(), module.__dict__)
+
+        sys.modules[abspath] = module
+
+    except Exception as exp:
+        log.exception("loading hook failed: {}".format(exp),
+                      exc_info=True)
+        return False
+
+    obj = getattr(module, class_name)
+    hook_obj = obj()
+    ret_val = hook_obj.execute(*args, **kwargs)
+    return ret_val