check if ast.JoinedStr exists before using it
ast.JoinedStr is new in Python3.6 (it's f-strings), it does not exist in Pythons below that
@@ -94,7 +94,7 @@ def _evaluate_ast(node):
statement = node.s
# Hierarchy for "".format() is Wrapper -> Call -> Attribute -> Str
wrapper = node.parent.parent.parent
- elif isinstance(node.parent, ast.JoinedStr):
+ elif hasattr(ast, 'JoinedStr') and isinstance(node.parent, ast.JoinedStr):
statement = node.s
wrapper = node.parent.parent
