fix(typing): explicitly define Match and Pattern on Import Error (python < 3.7)

for python < 3.6 those two types are not defined. In case of import error, let's
define them (in the exact same way they are defined in the re module of python
>= 3.7).

2 files changed, 23 insertions, 2 deletions

diff --git a/logilab/common/pytest.py b/logilab/common/pytest.py
index e0758c4..b7f2e83 100644
--- a/logilab/common/pytest.py
+++ b/logilab/common/pytest.py
@@ -100,7 +100,17 @@ import re
 import sys
 import os.path as osp
 from time import process_time, time
-from re import Match  # type: ignore
+
+try:
+    from re import Match  # type: ignore
+except ImportError:
+    # Match is python > 3.6 only.
+    #
+    # To be compatible with python <= 3.6, and still provide some typing, we
+    # manually define Match, in the same manner it is defined in the re module
+    # of python > 3.7
+    # cf https://github.com/python/cpython/blob/3.7/Lib/re.py#L264
+    Match = type(re.sre_compile.compile("", 0).match(""))  # type: ignore
 import warnings
 import types
 import inspect
diff --git a/logilab/common/textutils.py b/logilab/common/textutils.py
index cfb48d7..d8cad1f 100644
--- a/logilab/common/textutils.py
+++ b/logilab/common/textutils.py
@@ -46,7 +46,18 @@ __docformat__ = "restructuredtext en"
 import sys
 import re
 import os.path as osp
-from re import Pattern, Match  # type: ignore
+
+try:
+    from re import Pattern, Match  # type: ignore
+except ImportError:
+    # Pattern and Match are python > 3.6 only.
+    #
+    # To be compatible with python <= 3.6, and still provide some typing, we
+    # manually define Pattern and Match, in the same manner they are defined in
+    # the re module of python > 3.7
+    # cf https://github.com/python/cpython/blob/3.7/Lib/re.py#L264
+    Pattern = type(re.sre_compile.compile("", 0))  # type: ignore
+    Match = type(re.sre_compile.compile("", 0).match(""))  # type: ignore
 from warnings import warn
 from unicodedata import normalize as _uninormalize
 from typing import Any, Optional, Tuple, List, Callable, Dict, Union