Add is_sequence util function

This is a helper for identifying whether the var is a sequence,
but is not of string-like type (optionally).

Co-authored-by: Toshio Kuratomi <toshio@fedoraproject.org>
Co-authored-by: Brian Coca <briancoca+dev@gmail.com>
Co-authored-by: Abhijeet Kasurde <akasurde@redhat.com>

lib/ansible/module_utils/common/collections.py

@@ -0,0 +1,29 @@
+# Copyright (c), Sviatoslav Sydorenko <ssydoren@redhat.com> 2018
+# Simplified BSD License (see licenses/simplified_bsd.txt or https://opensource.org/licenses/BSD-2-Clause)
+"""Collection of low-level utility functions."""
+
+from __future__ import absolute_import, division, print_function
+__metaclass__ = type
+
+
+from ..six import binary_type, text_type
+from ._collections_compat import Sequence
+
+
+def is_string(seq):
+    """Identify whether the input has a string-like type (inclding bytes)."""
+    return isinstance(seq, (text_type, binary_type))
+
+
+def is_sequence(seq, include_strings=False):
+    """Identify whether the input is a sequence.
+
+    Strings and bytes are not sequences here,
+    unless ``include_string`` is ``True``.
+
+    Non-indexable things are never of a sequence type.
+    """
+    if not include_strings and is_string(seq):
+        return False
+
+    return isinstance(seq, Sequence)