% operation returned both left and right side, but only the left side is really important.

jedi/evaluate/precedence.py

@@ -244,4 +244,8 @@ def _element_calculate(evaluator, left, operator, right):
     elif operator == '-':
         if _is_number(left) and _is_number(right):
             return [create(evaluator, left.obj - right.obj)]
+    elif operator == '%':
+        # With strings and numbers the left type typically remains. Except for
+        # `int() % float()`.
+        return [left]
     return [left, right]

test/static_analysis/attribute_error.py

@@ -84,3 +84,13 @@ return_one(''.undefined_attribute)
 @undefined_decorator
 def func():
     return 1
+
+# -----------------
+# operators
+# -----------------
+
+string = '%s %s' % (1, 2)
+
+# Shouldn't raise an error, because `string` is really just a string, not an
+# array or something.
+string.upper