diff --git a/jedi/inference/compiled/subprocess/functions.py b/jedi/inference/compiled/subprocess/functions.py
index baa5c328..2d3ab607 100644
--- a/jedi/inference/compiled/subprocess/functions.py
+++ b/jedi/inference/compiled/subprocess/functions.py
@@ -1,6 +1,5 @@
 import sys
 import os
-import re
 import inspect
 import importlib
 import warnings
@@ -102,10 +101,9 @@ def _iter_module_names(inference_state, paths):
             name = dir_entry.name
             # First Namespaces then modules/stubs
             if dir_entry.is_dir():
-                # pycache is obviously not an interestin namespace. Also the
+                # pycache is obviously not an interesting namespace. Also the
                 # name must be a valid identifier.
-                # TODO use str.isidentifier, once Python 2 is removed
-                if name != '__pycache__' and not re.search(r'\W|^\d', name):
+                if name != '__pycache__' and name.isidentifier():
                     yield name
             else:
                 if name.endswith('.pyi'):  # Stub files
diff --git a/jedi/inference/gradual/annotation.py b/jedi/inference/gradual/annotation.py
index cfc6c733..fa3aa5ae 100644
--- a/jedi/inference/gradual/annotation.py
+++ b/jedi/inference/gradual/annotation.py
@@ -138,8 +138,7 @@ def _infer_param(function_value, param):
     """
     annotation = param.annotation
     if annotation is None:
-        # If no Python 3-style annotation, look for a Python 2-style comment
-        # annotation.
+        # If no Python 3-style annotation, look for a comment annotation.
         # Identify parameters to function in the same sequence as they would
         # appear in a type comment.
         all_params = [child for child in param.parent.children
@@ -204,7 +203,8 @@ def infer_return_types(function, arguments):
     all_annotations = py__annotations__(function.tree_node)
     annotation = all_annotations.get("return", None)
     if annotation is None:
-        # If there is no Python 3-type annotation, look for a Python 2-type annotation
+        # If there is no Python 3-type annotation, look for an annotation
+        # comment.
         node = function.tree_node
         comment = parser_utils.get_following_comment_same_line(node)
         if comment is None:
diff --git a/jedi/inference/gradual/typeshed.py b/jedi/inference/gradual/typeshed.py
index a7aadb09..2f7dcf55 100644
--- a/jedi/inference/gradual/typeshed.py
+++ b/jedi/inference/gradual/typeshed.py
@@ -272,7 +272,7 @@ def _load_from_typeshed(inference_state, python_value_set, parent_module_value,
 def _try_to_load_stub_from_file(inference_state, python_value_set, file_io, import_names):
     try:
         stub_module_node = parse_stub_module(inference_state, file_io)
-    except OSError:  # IOError is Python 2 only
+    except OSError:
         # The file that you're looking for doesn't exist (anymore).
         return None
     else: