added example on how to use the day_of_week namespace

ibis/backends/sql/compiler.py

@@ -787,7 +787,7 @@ def visit_DayOfWeekIndex(self, op, *, arg):
         return (self.f.dayofweek(arg) + 6) % 7
 
     def visit_IsoDayOfWeekIndex(self, op, *, arg):
-        return self.f.dayofweek(arg)
+        return  (self.f.dayofweek(arg) + 6) % 7+1
 
 
     def visit_DayOfWeekName(self, op, *, arg):
@@ -799,15 +799,6 @@ def visit_DayOfWeekName(self, op, *, arg):
             ifs=list(itertools.starmap(self.if_, enumerate(calendar.day_name))),
         )
 
-    def visit_DayOfWeekName(self, op, *, arg):
-        # day of week number is 0-indexed
-        # Sunday == 0
-        # Saturday == 6
-        return sge.Case(
-            this=self.f.dayofweek(arg),
-            ifs=list(itertools.starmap(self.if_, enumerate(calendar.day_name))),
-        )
-
     def visit_IntervalFromInteger(self, op, *, arg, unit):
         return sge.Interval(
             this=sge.convert(arg), unit=sge.Var(this=unit.singular.upper())

ibis/expr/operations/temporal.py

@@ -164,12 +164,23 @@ class DayOfWeekIndex(Unary):
 
     dtype = dt.int16
 
+@public
+class IsoDayOfWeekIndex(Unary):
+    arg: Value[dt.Date | dt.Timestamp]
+
+    dtype = dt.int16
+
 
 @public
 class DayOfWeekName(Unary):
     arg: Value[dt.Date | dt.Timestamp]
 
     dtype = dt.string
+@public
+class IsoDayOfWeekName(Unary):
+    arg: Value[dt.Date | dt.Timestamp]
+
+    dtype = dt.string
 
 
 @public

ibis/expr/types/temporal.py

@@ -41,19 +41,40 @@ def day(self) -> ir.IntegerValue:
         """Extract the day component."""
         return ops.ExtractDay(self).to_expr()
 
-    def isoday_of_week(self) -> ir.IntegerValue:
-        """Extract the day of the week component in ISO-Format (1=Monday, 7=Sunday)."""
-        return ops.ExtractDayOfWeek(self).to_expr()
-
     @property
     def day_of_week(self) -> DayOfWeek:
         """A namespace of methods for extracting day of week information.
 
         Returns
         -------
         DayOfWeek
-            An namespace expression containing methods to use to extract
+            An namespace expression containing methods to extract
             information.
+
+        Examples
+        --------
+        >>> import ibis
+        >>> import datetime as dt 
+        >>> ibis.options.interactive = True
+        >>> t = ibis.memtable({"date" : [dt.datetime(2024,4,x) for x in [14,15,16,17,18,19,20]]}, name="t")
+        >>> t.mutate(
+        ...    day_of_week=_.date.day_of_week.index(),
+        ...    day_of_week_name=_.date.day_of_week.full_name(),
+        ...    iso_day_of_week=_.date.day_of_week.iso_index()
+        ...    )
+        ┏━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━┓
+        ┃ date                ┃ day_of_week ┃ day_of_week_name ┃ iso_day_of_week ┃
+        ┡━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━┩
+        │ timestamp           │ int16       │ string           │ int16           │
+        ├─────────────────────┼─────────────┼──────────────────┼─────────────────┤
+        │ 2024-04-14 00:00:00 │           6 │ Sunday           │               7 │
+        │ 2024-04-15 00:00:00 │           0 │ Monday           │               1 │
+        │ 2024-04-16 00:00:00 │           1 │ Tuesday          │               2 │
+        │ 2024-04-17 00:00:00 │           2 │ Wednesday        │               3 │
+        │ 2024-04-18 00:00:00 │           3 │ Thursday         │               4 │
+        │ 2024-04-19 00:00:00 │           4 │ Friday           │               5 │
+        │ 2024-04-20 00:00:00 │           5 │ Saturday         │               6 │
+        └─────────────────────┴─────────────┴──────────────────┴─────────────────┘
         """
         return DayOfWeek(self)
 
@@ -988,3 +1009,15 @@ def full_name(self):
             The name of the day of the week
         """
         return ops.DayOfWeekName(self._expr).to_expr()
+
+
+    def iso_index(self):
+        """Get the index of the day of the week in iso-format (1=Monday, 7=Sunday).
+
+        Returns
+        -------
+        IntegerValue
+            The index of the day of the week in iso-format (1=Monday, 7=Sunday).
+        """
+        return ops.IsoDayOfWeekIndex(self._expr).to_expr()
+