From bcd20c7ecae292df9eca455e52c8c77638b185ca Mon Sep 17 00:00:00 2001
From: mwmajewsk <5279578+mmajewsk@users.noreply.github.com>
Date: Wed, 20 Jun 2018 22:44:49 +0200
Subject: [PATCH] Update util.py - fix ensure_tuple instance check

doing isinstance(obj, Sequence) makes calls with keys of dict impossible
Example:
Returns
```
d = {'a':'a', 'b':'b'}
table.upsert(values, d.keys())
```
`dict_keys(['a', 'b'])` is not of instance Sequence, but Iterable, therefore `ensure_tuple(dict_keys(['a', 'b']))` returns (dict_keys(['a', 'b']),)
which leads to invalid iteration.
---
 dataset/util.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/dataset/util.py b/dataset/util.py
index 57fec8f..b1a0390 100644
--- a/dataset/util.py
+++ b/dataset/util.py
@@ -1,6 +1,6 @@
 import six
 from hashlib import sha1
-from collections import OrderedDict, Sequence
+from collections import OrderedDict, Iterable
 from six.moves.urllib.parse import urlparse
 
 QUERY_STEP = 1000
@@ -99,7 +99,7 @@ def ensure_tuple(obj):
     """Try and make the given argument into a tuple."""
     if obj is None:
         return tuple()
-    if isinstance(obj, Sequence) and not isinstance(obj, six.string_types):
+    if isinstance(obj, Iterable) and not isinstance(obj, six.string_types):
         return tuple(obj)
     return obj,