Use f-strings for string formatting

Author: WhyNotHugo

khal/controllers.py

@@ -72,7 +72,7 @@ def format_day(day: dt.date, format_string: str, locale, attributes=None):
     try:
         return format_string.format(**attributes) + colors["reset"]
     except (KeyError, IndexError):
-        raise KeyError("cannot format day with: %s" % format_string)
+        raise KeyError(f"cannot format day with: {format_string}")
 
 
 def calendar(

khal/parse_datetime.py

@@ -122,7 +122,7 @@ def weekdaypstr(dayname: str) -> int:
         return 5
     if dayname in ['sunday', 'sun']:
         return 6
-    raise ValueError('invalid weekday name `%s`' % dayname)
+    raise ValueError(f'invalid weekday name `{dayname}`')
 
 
 def construct_daynames(date_: dt.date) -> str:

khal/ui/__init__.py

@@ -794,7 +794,7 @@ def export_this(_, user_data):
                 self.focus_event.event.export_ics(user_data.get_edit_text())
             except Exception as error:
                 self.pane.window.backtrack()
-                self.pane.window.alert(('alert', 'Failed to save event: %s' % error))
+                self.pane.window.alert(('alert', f'Failed to save event: {error}'))
             else:
                 self.pane.window.backtrack()
                 self.pane.window.alert('Event successfully exported')

khal/ui/calendarwidget.py

@@ -182,7 +182,7 @@ def set_focus_date(self, a_date: dt.date) -> None:
             if day[0].date == a_date:
                 self.focus_position = num
                 return None
-        raise ValueError('%s not found in this week' % a_date)
+        raise ValueError(f'{a_date} not found in this week')
 
     def get_date_column(self, a_date: dt.date) -> int:
         """return the column `a_date` is in, raises ValueError if `a_date`
@@ -191,7 +191,7 @@ def get_date_column(self, a_date: dt.date) -> int:
         for num, day in enumerate(self.contents[1:8], 1):
             if day[0].date == a_date:
                 return num
-        raise ValueError('%s not found in this week' % a_date)
+        raise ValueError(f'{a_date} not found in this week')
 
     def keypress(self, size: tuple[int], key: str) -> str:
         """only leave calendar area on pressing 'tab' or 'enter'"""

khal/ui/editor.py

@@ -551,7 +551,7 @@ def export_this(_, user_data):
                 self.pane.window.backtrack()
                 self.pane.window.alert(
                     ('light red',
-                     'Failed to save event: %s' % e))
+                     f'Failed to save event: {e}'))
                 return
 
             self.pane.window.backtrack()
@@ -851,7 +851,7 @@ def __init__(self, this_func, abort_func, event) -> None:
         lines.append(urwid.Text('Export event as ICS file'))
         lines.append(urwid.Text(''))
         export_location = ExtendedEdit(
-            caption='Location: ', edit_text="~/%s.ics" % event.summary.strip())
+            caption='Location: ', edit_text=f"~/{event.summary.strip()}.ics")
         lines.append(export_location)
         lines.append(urwid.Divider(' '))
         lines.append(CAttrMap(