Bug 1281004: factor out searching for python objects by path; r=gps

MozReview-Commit-ID: 4ioEqPA7BQk

taskcluster/taskgraph/util/python_path.py

@@ -0,0 +1,27 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+from __future__ import absolute_import, print_function, unicode_literals
+
+
+def find_object(path):
+    """
+    Find a Python object given a path of the form <modulepath>:<objectpath>.
+    Conceptually equivalent to
+
+        def find_object(modulepath, objectpath):
+            import <modulepath> as mod
+            return mod.<objectpath>
+    """
+    if path.count(':') != 1:
+        raise ValueError(
+            'python path {!r} does not have the form "module:object"'.format(path))
+
+    modulepath, objectpath = path.split(':')
+    obj = __import__(modulepath)
+    for a in modulepath.split('.')[1:]:
+        obj = getattr(obj, a)
+    for a in objectpath.split('.'):
+        obj = getattr(obj, a)
+    return obj