diff --git a/jedi/api/__init__.py b/jedi/api/__init__.py
index bb9be477..035ade2f 100644
--- a/jedi/api/__init__.py
+++ b/jedi/api/__init__.py
@@ -348,7 +348,7 @@ class Script(object):
                     types = context.eval_node(node)
                     for testlist in node.children[:-1:2]:
                         # Iterate tuples.
-                        unpack_tuple_to_dict(self._evaluator, types, testlist)
+                        unpack_tuple_to_dict(context, types, testlist)
                 else:
                     try_iter_content(self._evaluator.goto_definitions(context, node))
                 self._evaluator.reset_recursion_limitations()
diff --git a/jedi/evaluate/__init__.py b/jedi/evaluate/__init__.py
index 8f8f2856..c5c6a78a 100644
--- a/jedi/evaluate/__init__.py
+++ b/jedi/evaluate/__init__.py
@@ -80,6 +80,7 @@ from jedi.evaluate import helpers
 from jedi.evaluate import pep0484
 from jedi.evaluate.filters import TreeNameDefinition, ParamName
 from jedi.evaluate.instance import AnonymousInstance, BoundMethod
+from jedi.evaluate.context import ContextualizedName, ContextualizedNode
 
 
 class Evaluator(object):
@@ -150,7 +151,8 @@ class Evaluator(object):
         types = self.eval_element(context, rhs)
 
         if seek_name:
-            types = finder.check_tuple_assignments(self, types, seek_name)
+            c_node = ContextualizedName(context, seek_name)
+            types = finder.check_tuple_assignments(self, c_node, types)
 
         first_operation = stmt.first_operation()
         if first_operation not in ('=', None) and first_operation.type == 'operator':
@@ -168,8 +170,8 @@ class Evaluator(object):
                 # only in for loops without clutter, because they are
                 # predictable. Also only do it, if the variable is not a tuple.
                 node = for_stmt.get_input_node()
-                for_iterables = self.eval_element(context, node)
-                ordered = list(iterable.py__iter__(self, for_iterables, node))
+                cn = ContextualizedNode(context, node)
+                ordered = list(iterable.py__iter__(self, cn.infer(), cn))
 
                 for lazy_context in ordered:
                     dct = {str(for_stmt.children[1]): lazy_context.infer()}
@@ -451,8 +453,10 @@ class Evaluator(object):
                 return self.eval_statement(context, def_, name)
             elif def_.type == 'for_stmt':
                 container_types = self.eval_element(context, def_.children[3])
-                for_types = iterable.py__iter__types(self, container_types, def_.children[3])
-                return finder.check_tuple_assignments(self, for_types, name)
+                cn = ContextualizedNode(context, def_.children[3])
+                for_types = iterable.py__iter__types(self, container_types, cn)
+                c_node = ContextualizedName(context, name)
+                return finder.check_tuple_assignments(self, c_node, for_types)
             elif def_.type in ('import_from', 'import_name'):
                 return imports.infer_import(context, name)
 
diff --git a/jedi/evaluate/analysis.py b/jedi/evaluate/analysis.py
index 29cf614b..46a4145d 100644
--- a/jedi/evaluate/analysis.py
+++ b/jedi/evaluate/analysis.py
@@ -82,6 +82,7 @@ def add(node_context, error_name, node, message=None, typ=Error, payload=None):
 
     # TODO this path is probably not right
     module_context = node_context.get_root_context()
+    print(module_context, node)
     module_path = module_context.py__file__()
     instance = typ(error_name, module_path, node.start_pos, message)
     debug.warning(str(instance), format=False)
diff --git a/jedi/evaluate/context.py b/jedi/evaluate/context.py
index 2cfc8251..03a869de 100644
--- a/jedi/evaluate/context.py
+++ b/jedi/evaluate/context.py
@@ -1,5 +1,6 @@
 from jedi._compatibility import Python3Method
 from jedi.common import unite
+from jedi.parser.python.tree import ExprStmt, CompFor
 
 
 class Context(object):
@@ -14,9 +15,6 @@ class Context(object):
         self.evaluator = evaluator
         self.parent_context = parent_context
 
-    def get_parent_flow_context(self):
-        return self.parent_context
-
     def get_root_context(self):
         context = self
         while True:
@@ -76,12 +74,6 @@ class TreeContext(Context):
         return '<%s: %s>' % (self.__class__.__name__, self.tree_node)
 
 
-class FlowContext(TreeContext):
-    def get_parent_flow_context(self):
-        if 1:
-            return self.parent_context
-
-
 class AbstractLazyContext(object):
     def __init__(self, data):
         self.data = data
@@ -141,3 +133,51 @@ class MergedLazyContexts(AbstractLazyContext):
     """data is a list of lazy contexts."""
     def infer(self):
         return unite(l.infer() for l in self.data)
+
+
+class ContextualizedNode(object):
+    def __init__(self, context, node):
+        self.context = context
+        self._node = node
+
+    def get_root_context(self):
+        return self.context.get_root_context()
+
+    def infer(self):
+        return self.context.eval_node(self._node)
+
+
+class ContextualizedName(ContextualizedNode):
+    # TODO merge with TreeNameDefinition?!
+    @property
+    def name(self):
+        return self._node
+
+    def assignment_indexes(self):
+        """
+        Returns an array of tuple(int, node) of the indexes that are used in
+        tuple assignments.
+
+        For example if the name is ``y`` in the following code::
+
+            x, (y, z) = 2, ''
+
+        would result in ``[(1, xyz_node), (0, yz_node)]``.
+        """
+        indexes = []
+        node = self._node.parent
+        compare = self._node
+        while node is not None:
+            if node.type in ('testlist_comp', 'testlist_star_expr', 'exprlist'):
+                for i, child in enumerate(node.children):
+                    if child == compare:
+                        indexes.insert(0, (int(i / 2), node))
+                        break
+                else:
+                    raise LookupError("Couldn't find the assignment.")
+            elif isinstance(node, (ExprStmt, CompFor)):
+                break
+
+            compare = node
+            node = node.parent
+        return indexes
diff --git a/jedi/evaluate/filters.py b/jedi/evaluate/filters.py
index 2a7dc50e..7bb2c872 100644
--- a/jedi/evaluate/filters.py
+++ b/jedi/evaluate/filters.py
@@ -73,9 +73,6 @@ class ContextName(ContextNameMixin, AbstractTreeName):
 
 
 class TreeNameDefinition(AbstractTreeName):
-    def get_parent_flow_context(self):
-        return self.parent_context
-
     def infer(self):
         # Refactor this, should probably be here.
         from jedi.evaluate.finder import _name_to_types
diff --git a/jedi/evaluate/finder.py b/jedi/evaluate/finder.py
index 8d624da0..ce5f9b27 100644
--- a/jedi/evaluate/finder.py
+++ b/jedi/evaluate/finder.py
@@ -30,6 +30,7 @@ from jedi.evaluate import flow_analysis
 from jedi.evaluate import param
 from jedi.evaluate import helpers
 from jedi.evaluate.filters import get_global_filters
+from jedi.evaluate.context import ContextualizedName, ContextualizedNode
 
 
 class NameFinder(object):
@@ -183,9 +184,10 @@ def _name_to_types(evaluator, context, tree_name):
         try:
             types = context.predefined_names[node][tree_name.value]
         except KeyError:
-            container_types = context.eval_node(node.children[3])
-            for_types = iterable.py__iter__types(evaluator, container_types, node.children[3])
-            types = check_tuple_assignments(evaluator, for_types, tree_name)
+            cn = ContextualizedNode(context, node.children[3])
+            for_types = iterable.py__iter__types(evaluator, cn.infer(), cn)
+            c_node = ContextualizedName(context, tree_name)
+            types = check_tuple_assignments(evaluator, c_node, for_types)
     elif node.type == 'expr_stmt':
         types = _remove_statements(evaluator, context, node, tree_name)
     elif node.type == 'with_stmt':
@@ -360,13 +362,14 @@ def _check_isinstance_type(context, element, search_name):
     return result
 
 
-def check_tuple_assignments(evaluator, types, name):
+def check_tuple_assignments(evaluator, contextualized_name, types):
     """
     Checks if tuples are assigned.
     """
     lazy_context = None
-    for index, node in name.assignment_indexes():
-        iterated = iterable.py__iter__(evaluator, types, node)
+    for index, node in contextualized_name.assignment_indexes():
+        cn = ContextualizedNode(contextualized_name.context, node)
+        iterated = iterable.py__iter__(evaluator, types, cn)
         for _ in range(index + 1):
             try:
                 lazy_context = next(iterated)
diff --git a/jedi/evaluate/imports.py b/jedi/evaluate/imports.py
index 566cd979..f0949b61 100644
--- a/jedi/evaluate/imports.py
+++ b/jedi/evaluate/imports.py
@@ -297,7 +297,7 @@ class Importer(object):
                 method = parent_module.py__path__
             except AttributeError:
                 # The module is not a package.
-                _add_error(parent_module, import_path[-1])
+                _add_error(self.module_context, import_path[-1])
                 return set()
             else:
                 paths = method()
@@ -314,7 +314,7 @@ class Importer(object):
                     except ImportError:
                         module_path = None
                 if module_path is None:
-                    _add_error(parent_module, import_path[-1])
+                    _add_error(self.module_context, import_path[-1])
                     return set()
         else:
             parent_module = None
diff --git a/jedi/evaluate/iterable.py b/jedi/evaluate/iterable.py
index 6dd82f2b..f482fac4 100644
--- a/jedi/evaluate/iterable.py
+++ b/jedi/evaluate/iterable.py
@@ -240,23 +240,24 @@ class Comprehension(AbstractSequence):
         parent_context = parent_context or self._defining_context
         input_types = parent_context.eval_node(input_node)
 
-        iterated = py__iter__(evaluator, input_types, input_node)
+        cn = context.ContextualizedNode(parent_context, input_node)
+        iterated = py__iter__(evaluator, input_types, cn)
         exprlist = comp_for.children[1]
         for i, lazy_context in enumerate(iterated):
             types = lazy_context.infer()
-            dct = unpack_tuple_to_dict(evaluator, types, exprlist)
-            context = self._get_comp_for_context(
+            dct = unpack_tuple_to_dict(parent_context, types, exprlist)
+            context_ = self._get_comp_for_context(
                 parent_context,
                 comp_for,
             )
-            with helpers.predefine_names(context, comp_for, dct):
+            with helpers.predefine_names(context_, comp_for, dct):
                 try:
-                    for result in self._nested(comp_fors[1:], context):
+                    for result in self._nested(comp_fors[1:], context_):
                         yield result
                 except IndexError:
-                    iterated = context.eval_node(self._eval_node())
+                    iterated = context_.eval_node(self._eval_node())
                     if self.array_type == 'dict':
-                        yield iterated, context.eval_node(self._eval_node(2))
+                        yield iterated, context_.eval_node(self._eval_node(2))
                     else:
                         yield iterated
 
@@ -561,33 +562,33 @@ class MergedArray(_FakeArray):
         return sum(len(a) for a in self._arrays)
 
 
-def unpack_tuple_to_dict(evaluator, types, exprlist):
+def unpack_tuple_to_dict(context, types, exprlist):
     """
     Unpacking tuple assignments in for statements and expr_stmts.
     """
     if exprlist.type == 'name':
         return {exprlist.value: types}
     elif exprlist.type == 'atom' and exprlist.children[0] in '([':
-        return unpack_tuple_to_dict(evaluator, types, exprlist.children[1])
+        return unpack_tuple_to_dict(context, types, exprlist.children[1])
     elif exprlist.type in ('testlist', 'testlist_comp', 'exprlist',
                            'testlist_star_expr'):
         dct = {}
         parts = iter(exprlist.children[::2])
         n = 0
-        for lazy_context in py__iter__(evaluator, types, exprlist):
+        for lazy_context in py__iter__(context.evaluator, types, exprlist):
             n += 1
             try:
                 part = next(parts)
             except StopIteration:
                 # TODO this context is probably not right.
-                analysis.add(next(iter(types)), 'value-error-too-many-values', part,
+                analysis.add(context, 'value-error-too-many-values', part,
                              message="ValueError: too many values to unpack (expected %s)" % n)
             else:
-                dct.update(unpack_tuple_to_dict(evaluator, lazy_context.infer(), part))
+                dct.update(unpack_tuple_to_dict(context, lazy_context.infer(), part))
         has_parts = next(parts, None)
         if types and has_parts is not None:
             # TODO this context is probably not right.
-            analysis.add(next(iter(types)), 'value-error-too-few-values', has_parts,
+            analysis.add(context, 'value-error-too-few-values', has_parts,
                          message="ValueError: need more than %s values to unpack" % n)
         return dct
     elif exprlist.type == 'power' or exprlist.type == 'atom_expr':
@@ -601,17 +602,19 @@ def unpack_tuple_to_dict(evaluator, types, exprlist):
     raise NotImplementedError
 
 
-def py__iter__(evaluator, types, node=None):
+def py__iter__(evaluator, types, contextualized_node=None):
     debug.dbg('py__iter__')
     type_iters = []
     for typ in types:
         try:
             iter_method = typ.py__iter__
         except AttributeError:
-            if node is not None:
-                # TODO this context is probably not right.
-                analysis.add(typ, 'type-error-not-iterable', node,
-                             message="TypeError: '%s' object is not iterable" % typ)
+            if contextualized_node is not None:
+                analysis.add(
+                    contextualized_node.context,
+                    'type-error-not-iterable',
+                    contextualized_node._node,
+                    message="TypeError: '%s' object is not iterable" % typ)
         else:
             type_iters.append(iter_method())
 
@@ -621,12 +624,15 @@ def py__iter__(evaluator, types, node=None):
         )
 
 
-def py__iter__types(evaluator, types, node=None):
+def py__iter__types(evaluator, types, contextualized_node=None):
     """
     Calls `py__iter__`, but ignores the ordering in the end and just returns
     all types that it contains.
     """
-    return unite(lazy_context.infer() for lazy_context in py__iter__(evaluator, types, node))
+    return unite(
+        lazy_context.infer()
+        for lazy_context in py__iter__(evaluator, types, contextualized_node)
+    )
 
 
 def py__getitem__(evaluator, context, types, trailer):
diff --git a/jedi/evaluate/representation.py b/jedi/evaluate/representation.py
index 9d4a728b..1afa89b4 100644
--- a/jedi/evaluate/representation.py
+++ b/jedi/evaluate/representation.py
@@ -61,6 +61,7 @@ from jedi.evaluate.filters import ParserTreeFilter, FunctionExecutionFilter, \
     ContextNameMixin
 from jedi.evaluate.dynamic import search_params
 from jedi.evaluate import context
+from jedi.evaluate.context import ContextualizedNode
 
 
 def apply_py__get__(context, base_context):
@@ -315,8 +316,8 @@ class FunctionExecutionContext(context.TreeContext):
     def _eval_yield(self, yield_expr):
         node = yield_expr.children[1]
         if node.type == 'yield_arg':  # It must be a yield from.
-            yield_from_types = self.eval_node(node.children[1])
-            for lazy_context in iterable.py__iter__(self.evaluator, yield_from_types, node):
+            cn = ContextualizedNode(self, node.children[1])
+            for lazy_context in iterable.py__iter__(self.evaluator, cn.infer(), cn):
                 yield lazy_context
         else:
             yield context.LazyTreeContext(self, node)
@@ -360,8 +361,8 @@ class FunctionExecutionContext(context.TreeContext):
                         yield result
             else:
                 input_node = for_stmt.get_input_node()
-                for_types = self.eval_node(input_node)
-                ordered = iterable.py__iter__(evaluator, for_types, input_node)
+                cn = ContextualizedNode(self, input_node)
+                ordered = iterable.py__iter__(evaluator, cn.infer(), cn)
                 ordered = list(ordered)
                 for lazy_context in ordered:
                     dct = {str(for_stmt.children[1]): lazy_context.infer()}
diff --git a/jedi/evaluate/stdlib.py b/jedi/evaluate/stdlib.py
index 55ee68ea..e71f9d18 100644
--- a/jedi/evaluate/stdlib.py
+++ b/jedi/evaluate/stdlib.py
@@ -12,7 +12,6 @@ compiled module that returns the types for C-builtins.
 import collections
 import re
 
-from jedi._compatibility import unicode
 from jedi.common import unite
 from jedi.evaluate import compiled
 from jedi.evaluate import representation as er
@@ -24,6 +23,7 @@ from jedi import debug
 from jedi.evaluate import precedence
 from jedi.evaluate import param
 from jedi.evaluate import analysis
+from jedi.evaluate.context import LazyTreeContext, ContextualizedNode
 
 
 class NotInStdLib(LookupError):
@@ -176,7 +176,11 @@ def builtins_reversed(evaluator, sequences, obj, arguments):
     # want static analysis to work well. Therefore we need to generated the
     # values again.
     key, lazy_context = next(arguments.unpack())
-    ordered = list(iterable.py__iter__(evaluator, sequences, lazy_context.data))
+    cn = None
+    if isinstance(lazy_context, LazyTreeContext):
+        # TODO access private
+        cn = ContextualizedNode(lazy_context._context, lazy_context.data)
+    ordered = list(iterable.py__iter__(evaluator, sequences, cn))
 
     rev = list(reversed(ordered))
     # Repack iterator values and then run it the normal way. This is
@@ -215,11 +219,12 @@ def builtins_isinstance(evaluator, objects, types, arguments):
                 bool_results.add(any(cls in mro for cls in classes))
             else:
                 _, lazy_context = list(arguments.unpack())[1]
-                node = lazy_context.data
-                message = 'TypeError: isinstance() arg 2 must be a ' \
-                          'class, type, or tuple of classes and types, ' \
-                          'not %s.' % cls_or_tup
-                analysis.add(cls_or_tup, 'type-error-isinstance', node, message)
+                if isinstance(lazy_context, LazyTreeContext):
+                    node = lazy_context.data
+                    message = 'TypeError: isinstance() arg 2 must be a ' \
+                              'class, type, or tuple of classes and types, ' \
+                              'not %s.' % cls_or_tup
+                    analysis.add(lazy_context._context, 'type-error-isinstance', node, message)
 
     return set(compiled.create(evaluator, x) for x in bool_results)
 
diff --git a/jedi/evaluate/sys_path.py b/jedi/evaluate/sys_path.py
index 513c32be..952d5bb8 100644
--- a/jedi/evaluate/sys_path.py
+++ b/jedi/evaluate/sys_path.py
@@ -10,6 +10,7 @@ from jedi.evaluate.cache import memoize_default
 from jedi import debug
 from jedi import common
 from jedi.evaluate.compiled import CompiledObject
+from jedi.evaluate.context import ContextualizedNode
 
 
 def get_venv_path(venv):
@@ -121,8 +122,8 @@ def _paths_from_assignment(module_context, expr_stmt):
 
         from jedi.evaluate.iterable import py__iter__
         from jedi.evaluate.precedence import is_string
-        types = module_context.create_context(expr_stmt).eval_node(expr_stmt)
-        for lazy_context in py__iter__(module_context.evaluator, types, expr_stmt):
+        cn = ContextualizedNode(module_context.create_context(expr_stmt), expr_stmt)
+        for lazy_context in py__iter__(module_context.evaluator, cn.infer(), cn):
             for context in lazy_context.infer():
                 if is_string(context):
                     yield context.obj
diff --git a/jedi/parser/python/tree.py b/jedi/parser/python/tree.py
index c6d8dd76..7f6a8b32 100644
--- a/jedi/parser/python/tree.py
+++ b/jedi/parser/python/tree.py
@@ -141,35 +141,6 @@ class PythonMixin():
                 break
         return scope
 
-    def assignment_indexes(self):
-        """
-        Returns an array of tuple(int, node) of the indexes that are used in
-        tuple assignments.
-
-        For example if the name is ``y`` in the following code::
-
-            x, (y, z) = 2, ''
-
-        would result in ``[(1, xyz_node), (0, yz_node)]``.
-        """
-        indexes = []
-        node = self.parent
-        compare = self
-        while node is not None:
-            if node.type in ('testlist_comp', 'testlist_star_expr', 'exprlist'):
-                for i, child in enumerate(node.children):
-                    if child == compare:
-                        indexes.insert(0, (int(i / 2), node))
-                        break
-                else:
-                    raise LookupError("Couldn't find the assignment.")
-            elif isinstance(node, (ExprStmt, CompFor)):
-                break
-
-            compare = node
-            node = node.parent
-        return indexes
-
     def is_scope(self):
         # Default is not being a scope. Just inherit from Scope.
         return False