Add a max_dynamic_params_depth setting to limit recusive searching for those params. It shouldn't be too crazy.

jedi/evaluate/__init__.py

@@ -89,6 +89,7 @@ class Evaluator(object):
         self.mixed_cache = {}  # see `evaluate.compiled.mixed.create()`
         self.analysis = []
         self.predefined_if_name_dict_dict = {}
+        self.dynamic_params_depth = 0
         self.is_analysis = False
 
         if sys_path is None:

jedi/evaluate/dynamic.py

@@ -52,8 +52,13 @@ def search_params(evaluator, param):
     is.
     """
     if not settings.dynamic_params:
-        return []
+        return set()
 
+    if evaluator.dynamic_params_depth == settings.max_dynamic_params_depth:
+        return set()
+
+    evaluator.dynamic_params_depth += 1
+    try:
         func = param.get_parent_until(tree.Function)
         debug.dbg('Dynamic param search for %s in %s.', param, str(func.name), color='MAGENTA')
         # Compare the param names.
@@ -63,6 +68,8 @@ def search_params(evaluator, param):
         result = set(chain.from_iterable(n.parent.eval(evaluator) for n in names))
         debug.dbg('Dynamic param result %s', result, color='MAGENTA')
         return result
+    finally:
+        evaluator.dynamic_params_depth -= 1
 
 
 @memoize_default([], evaluator_is_first_arg=True)

jedi/evaluate/representation.py

@@ -696,7 +696,7 @@ class FunctionExecution(Executed):
         else:
             yield self._evaluator.eval_element(element)
 
-    # TODO add execution_recursion_decorator?!
+    @recursion.execution_recursion_decorator
     def get_yield_types(self):
         yields = self.yields
         stopAt = tree.ForStmt, tree.WhileStmt, FunctionExecution, tree.IfStmt

jedi/settings.py

@@ -63,6 +63,7 @@ definitely worse in some cases. But a completion should also be fast.
 .. autodata:: max_function_recursion_level
 .. autodata:: max_executions_without_builtins
 .. autodata:: max_executions
+.. autodata:: max_dynamic_params_depth
 .. autodata:: scale_call_signatures
 
 
@@ -207,6 +208,12 @@ max_executions = 250
 A maximum amount of time, the completion may use.
 """
 
+max_dynamic_params_depth = 3
+"""
+A maximum amount of a recursive search function calls, when the type of a
+parameter is needed.
+"""
+
 scale_call_signatures = 0.1
 """
 Because call_signatures is normally used on every single key hit, it has

test/completion/stdlib.py

@@ -212,3 +212,12 @@ class B(object):
 cls = random.choice([A, B])
 #? ['say', 'shout']
 cls().s
+
+# -----------------
+# random
+# -----------------
+
+import zipfile
+z = zipfile.ZipFile("foo")
+#? ['upper']
+z.read('name').upper