SyntaxWarning with Python 3.12 and newer

[rhertzog]

With Python 3.12 and newer you get SyntaxWarning warnings when byte-compiling the hamster's code:

  /usr/lib/python3/dist-packages/hamster/lib/datetime.py:471:
SyntaxWarning: invalid escape sequence '\s'
    position="exact", separator="\s+", default_day=None, ref="now"):
  /usr/lib/python3/dist-packages/hamster/lib/datetime.py:472:
SyntaxWarning: invalid escape sequence '\s'
    """Parse a start-end range from text.
  /usr/lib/python3/dist-packages/hamster/widgets/activityentry.py:381:
SyntaxWarning: invalid escape sequence '\s'
    fragments = [f for f in re.split("[\s|#]", text)]
  /usr/lib/python3/dist-packages/hamster/widgets/timeinput.py:141:
SyntaxWarning: invalid escape sequence '\D'
    numbers = re.split("\D", str_time)

All those strings should be turned into regexp-quoted strings (with a leading r): r"\s+" for example.

(Initially reported in Debian here: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1085633)

[NightTsarina]

A simple patch to fix this issue:

diff --git a/src/hamster/lib/datetime.py b/src/hamster/lib/datetime.py
index ffd3d57..62f3010 100644
--- a/src/hamster/lib/datetime.py
+++ b/src/hamster/lib/datetime.py
@@ -468,14 +468,14 @@ class Range():
 
     @classmethod
     def parse(cls, text,
-              position="exact", separator="\s+", default_day=None, ref="now"):
+              position="exact", separator=r"\s+", default_day=None, ref="now"):
         """Parse a start-end range from text.
 
         position (str): "exact" to match exactly the full text
                         "head" to search only at the beginning of text, and
                         "tail" to search only at the end.
 
-        separator (str): regexp pattern (e.g. '\s+') meant to separate the datetime
+        separator (str): regexp pattern (e.g. r'\\s+') meant to separate the datetime
                          from the rest. Discarded for "exact" position.
 
         default_day (date): If start is given without any date (e.g. just hh:mm),
diff --git a/src/hamster/widgets/activityentry.py b/src/hamster/widgets/activityentry.py
index df68c04..68fc633 100644
--- a/src/hamster/widgets/activityentry.py
+++ b/src/hamster/widgets/activityentry.py
@@ -378,7 +378,7 @@ class CmdLineEntry(gtk.Entry):
                 break
 
 
-        fragments = [f for f in re.split("[\s|#]", text)]
+        fragments = [f for f in re.split(r"[\s|#]", text)]
         current_fragment = fragments[-1] if fragments else ""
 
 
diff --git a/src/hamster/widgets/timeinput.py b/src/hamster/widgets/timeinput.py
index b437696..4ef652c 100644
--- a/src/hamster/widgets/timeinput.py
+++ b/src/hamster/widgets/timeinput.py
@@ -138,7 +138,7 @@ class TimeInput(gtk.Entry):
 
         # strip everything non-numeric and consider hours to be first number
         # and minutes - second number
-        numbers = re.split("\D", str_time)
+        numbers = re.split(r"\D", str_time)
         numbers = [x for x in numbers if x!=""]
 
         hours, minutes = None, None