Fixed using deprecated escaping in regular expression in _strptime.py (issue23622).

Author: serhiy-storchaka

Lib/_strptime.py

@@ -253,8 +253,8 @@ def pattern(self, format):
         # format directives (%m, etc.).
         regex_chars = re_compile(r"([\\.^$*+?\(\){}\[\]|])")
         format = regex_chars.sub(r"\\\1", format)
-        whitespace_replacement = re_compile('\s+')
-        format = whitespace_replacement.sub('\s+', format)
+        whitespace_replacement = re_compile(r'\s+')
+        format = whitespace_replacement.sub(r'\\s+', format)
         while '%' in format:
             directive_index = format.index('%')+1
             processed_format = "%s%s%s" % (processed_format,

Lib/sre_parse.py

@@ -915,7 +915,7 @@ def addgroup(index):
                     if c in ASCIILETTERS:
                         import warnings
                         warnings.warn('bad escape %s' % this,
-                                      DeprecationWarning, stacklevel=5)
+                                      DeprecationWarning, stacklevel=4)
                 lappend(this)
         else:
             lappend(this)