diff --git a/jedi/evaluate/base_context.py b/jedi/evaluate/base_context.py
index e2e0a8e8..7559a6ca 100644
--- a/jedi/evaluate/base_context.py
+++ b/jedi/evaluate/base_context.py
@@ -93,7 +93,7 @@ class Context(BaseContext):
                 except ValueError:
                     pass
 
-            if type(index) not in (float, int, str, unicode, slice):
+            if type(index) not in (float, int, str, unicode, slice, bytes):
                 # If the index is not clearly defined, we have to get all the
                 # possiblities.
                 if isinstance(self, AbstractIterable) and self.array_type == 'dict':
diff --git a/jedi/evaluate/context/iterable.py b/jedi/evaluate/context/iterable.py
index 65f7cb09..ccdf5db3 100644
--- a/jedi/evaluate/context/iterable.py
+++ b/jedi/evaluate/context/iterable.py
@@ -22,6 +22,7 @@ It is important to note that:
 """
 from jedi import debug
 from jedi import settings
+from jedi._compatibility import force_unicode
 from jedi.evaluate import compiled
 from jedi.evaluate import analysis
 from jedi.evaluate import recursion
@@ -298,10 +299,11 @@ class SequenceLiteralContext(ArrayMixin, AbstractIterable):
     def py__getitem__(self, index):
         """Here the index is an int/str. Raises IndexError/KeyError."""
         if self.array_type == 'dict':
+            compiled_obj_index = compiled.create_simple_object(self.evaluator, index)
             for key, value in self._items():
                 for k in self._defining_context.eval_node(key):
                     if isinstance(k, compiled.CompiledObject) \
-                            and index == k.get_safe_value(default=None):
+                            and k.execute_operation(compiled_obj_index, '==').get_safe_value():
                         return self._defining_context.eval_node(value)
             raise KeyError('No key found in dictionary %s.' % self)
 
diff --git a/jedi/evaluate/helpers.py b/jedi/evaluate/helpers.py
index 84c8a668..25c28cb3 100644
--- a/jedi/evaluate/helpers.py
+++ b/jedi/evaluate/helpers.py
@@ -190,7 +190,11 @@ def is_compiled(context):
 
 
 def is_string(context):
-    return is_compiled(context) and isinstance(context.get_safe_value(default=None), (str, unicode))
+    if context.evaluator.environment.version_info.major == 2:
+        str_classes = (str, unicode, bytes)
+    else:
+        str_classes = (str,)
+    return is_compiled(context) and isinstance(context.get_safe_value(default=None), str_classes)
 
 
 def is_literal(context):