--- contrib/python/parso/py2/parso/cache.py	(working tree)
+++ contrib/python/parso/py2/parso/cache.py	(index)
@@ -142,6 +142,8 @@
 def _load_from_file_system(hashed_grammar, path, p_time, cache_path=None):
     cache_path = _get_hashed_path(hashed_grammar, path, cache_path=cache_path)
     try:
+        # SUBBOTNIK-2721 - Для безопасности отключаем загрузку с диска
+        raise FileNotFoundError
         try:
             if p_time > os.path.getmtime(cache_path):
                 # Cache is outdated
--- contrib/python/parso/py2/parso/file_io.py	(working tree)
+++ contrib/python/parso/py2/parso/file_io.py	(index)
@@ -1,6 +1,8 @@
 import os
 from parso._compatibility import FileNotFoundError
 
+import __res as res
+
 
 class FileIO(object):
     def __init__(self, path):
@@ -10,6 +12,9 @@
         # We would like to read unicode here, but we cannot, because we are not
         # sure if it is a valid unicode file. Therefore just read whatever is
         # here.
+        data = res.resfs_read(self.path)
+        if data:
+            return data
         with open(self.path, 'rb') as f:
             return f.read()
 
--- contrib/python/parso/py2/parso/grammar.py	(working tree)
+++ contrib/python/parso/py2/parso/grammar.py	(index)
@@ -1,5 +1,7 @@
 import hashlib
 import os
+import sys
+import pkgutil
 
 from parso._compatibility import FileNotFoundError, is_pypy
 from parso.pgen2 import generate_grammar
@@ -246,12 +248,15 @@
                 return _loaded_grammars[path]
             except KeyError:
                 try:
+                    bnf_text = pkgutil.get_data("parso", file)
+                    if bnf_text is None:
+                        raise FileNotFoundError
+                    if sys.version_info[0] == 3:
+                        bnf_text = bnf_text.decode("ascii")
-                    with open(path) as f:
-                        bnf_text = f.read()
 
                     grammar = PythonGrammar(version_info, bnf_text)
                     return _loaded_grammars.setdefault(path, grammar)
+                except (FileNotFoundError, IOError):
-                except FileNotFoundError:
                     message = "Python version %s.%s is currently not supported." % (version_info.major, version_info.minor)
                     raise NotImplementedError(message)
         else:
--- contrib/python/parso/py2/tests/conftest.py	(working tree)
+++ contrib/python/parso/py2/tests/conftest.py	(index)
@@ -6,6 +6,7 @@
 import os
 
 import pytest
+import yatest.common
 
 import parso
 from parso import cache
@@ -43,7 +44,7 @@
 
 def pytest_generate_tests(metafunc):
     if 'normalizer_issue_case' in metafunc.fixturenames:
+        base_dir = os.path.join(yatest.common.test_source_path(), 'normalizer_issue_files')
-        base_dir = os.path.join(os.path.dirname(__file__), 'test', 'normalizer_issue_files')
 
         cases = list(colllect_normalizer_tests(base_dir))
         metafunc.parametrize(
--- contrib/python/parso/py2/tests/test_cache.py	(working tree)
+++ contrib/python/parso/py2/tests/test_cache.py	(index)
@@ -36,6 +36,7 @@
     return cache_path
 
 
+@pytest.mark.skip("SUBBOTNIK-2721 Disable load cache from disk")
 def test_modulepickling_change_cache_dir(tmpdir):
     """
     ParserPickling should not save old cache when cache_directory is changed.
@@ -101,6 +102,7 @@
     assert cached2 is None
 
 
+@pytest.mark.skip
 def test_cache_limit():
     def cache_size():
         return sum(len(v) for v in parser_cache.values())
@@ -131,6 +133,7 @@
         return self._last_modified
 
 
+@pytest.mark.skip
 @pytest.mark.parametrize('diff_cache', [False, True])
 @pytest.mark.parametrize('use_file_io', [False, True])
 def test_cache_last_used_update(diff_cache, use_file_io):
@@ -177,6 +180,7 @@
     assert not old_paths.intersection(os.listdir(raw_cache_path))
 
 
+@pytest.mark.skip
 @skip_pypy
 def test_permission_error(monkeypatch):
     def save(*args, **kwargs):