Move get_item to a separate function

jedi/evaluate/__init__.py

@@ -67,6 +67,7 @@ from parso.python import tree
 import parso
 from parso import python_bytes_to_unicode
 
+from jedi._compatibility import unicode
 from jedi import debug
 from jedi import parser_utils
 from jedi.evaluate.utils import unite
@@ -83,6 +84,8 @@ from jedi.evaluate.context import ClassContext, FunctionContext, \
 from jedi.evaluate.context.iterable import CompForContext
 from jedi.evaluate.syntax_tree import eval_trailer, eval_expr_stmt, \
     eval_node, check_tuple_assignments
+from jedi.evaluate.helpers import EvaluatorIndexError, EvaluatorKeyError, \
+    EvaluatorTypeError
 
 
 def _execute(context, arguments):