make skip_nulls keyword-only where possible (#161)

Co-authored-by: MarcoGorelli <>

Author: MarcoGorelli

spec/API_specification/dataframe_api/column_object.py

@@ -270,7 +270,7 @@ def __invert__(self) -> Column:
             If any of the Column's columns is not boolean.
         """
 
-    def any(self, skip_nulls: bool = True) -> bool:
+    def any(self, *, skip_nulls: bool = True) -> bool:
         """
         Reduction returns a bool.
 
@@ -280,7 +280,7 @@ def any(self, skip_nulls: bool = True) -> bool:
             If column is not boolean.
         """
 
-    def all(self, skip_nulls: bool = True) -> bool:
+    def all(self, *, skip_nulls: bool = True) -> bool:
         """
         Reduction returns a bool.
 
@@ -290,56 +290,56 @@ def all(self, skip_nulls: bool = True) -> bool:
             If column is not boolean.
         """
 
-    def min(self, skip_nulls: bool = True) -> dtype:
+    def min(self, *, skip_nulls: bool = True) -> dtype:
         """
         Reduction returns a scalar. Any data type that supports comparisons
         must be supported. The returned value has the same dtype as the column.
         """
 
-    def max(self, skip_nulls: bool = True) -> dtype:
+    def max(self, *, skip_nulls: bool = True) -> dtype:
         """
         Reduction returns a scalar. Any data type that supports comparisons
         must be supported. The returned value has the same dtype as the column.
         """
 
-    def sum(self, skip_nulls: bool = True) -> dtype:
+    def sum(self, *, skip_nulls: bool = True) -> dtype:
         """
         Reduction returns a scalar. Must be supported for numerical and
         datetime data types. The returned value has the same dtype as the
         column.
         """
 
-    def prod(self, skip_nulls: bool = True) -> dtype:
+    def prod(self, *, skip_nulls: bool = True) -> dtype:
         """
         Reduction returns a scalar. Must be supported for numerical data types.
         The returned value has the same dtype as the column.
         """
 
-    def median(self, skip_nulls: bool = True) -> dtype:
+    def median(self, *, skip_nulls: bool = True) -> dtype:
         """
         Reduction returns a scalar. Must be supported for numerical and
         datetime data types. Returns a float for numerical data types, and
         datetime (with the appropriate timedelta format string) for datetime
         dtypes.
         """
 
-    def mean(self, skip_nulls: bool = True) -> dtype:
+    def mean(self, *, skip_nulls: bool = True) -> dtype:
         """
         Reduction returns a scalar. Must be supported for numerical and
         datetime data types. Returns a float for numerical data types, and
         datetime (with the appropriate timedelta format string) for datetime
         dtypes.
         """
 
-    def std(self, skip_nulls: bool = True) -> dtype:
+    def std(self, *, skip_nulls: bool = True) -> dtype:
         """
         Reduction returns a scalar. Must be supported for numerical and
         datetime data types. Returns a float for numerical data types, and
         datetime (with the appropriate timedelta format string) for datetime
         dtypes.
         """
 
-    def var(self, skip_nulls: bool = True) -> dtype:
+    def var(self, *, skip_nulls: bool = True) -> dtype:
         """
         Reduction returns a scalar. Must be supported for numerical and
         datetime data types. Returns a float for numerical data types, and

spec/API_specification/dataframe_api/dataframe_object.py

@@ -543,7 +543,7 @@ def __iter__(self) -> NoReturn:
         """
         raise NotImplementedError("'__iter__' is intentionally not implemented.")
 
-    def any(self, skip_nulls: bool = True) -> DataFrame:
+    def any(self, *, skip_nulls: bool = True) -> DataFrame:
         """
         Reduction returns a 1-row DataFrame.
 
@@ -554,7 +554,7 @@ def any(self, skip_nulls: bool = True) -> DataFrame:
         """
         ...
 
-    def all(self, skip_nulls: bool = True) -> DataFrame:
+    def all(self, *, skip_nulls: bool = True) -> DataFrame:
         """
         Reduction returns a 1-row DataFrame.
 
@@ -565,7 +565,7 @@ def all(self, skip_nulls: bool = True) -> DataFrame:
         """
         ...
 
-    def any_rowwise(self, skip_nulls: bool = True) -> Column:
+    def any_rowwise(self, *, skip_nulls: bool = True) -> Column:
         """
         Reduction returns a Column.
 
@@ -579,7 +579,7 @@ def any_rowwise(self, skip_nulls: bool = True) -> Column:
         """
         ...
 
-    def all_rowwise(self, skip_nulls: bool = True) -> Column:
+    def all_rowwise(self, *, skip_nulls: bool = True) -> Column:
         """
         Reduction returns a Column.
 
@@ -593,49 +593,49 @@ def all_rowwise(self, skip_nulls: bool = True) -> Column:
         """
         ...
 
-    def min(self, skip_nulls: bool = True) -> DataFrame:
+    def min(self, *, skip_nulls: bool = True) -> DataFrame:
         """
         Reduction returns a 1-row DataFrame.
         """
         ...
 
-    def max(self, skip_nulls: bool = True) -> DataFrame:
+    def max(self, *, skip_nulls: bool = True) -> DataFrame:
         """
         Reduction returns a 1-row DataFrame.
         """
         ...
 
-    def sum(self, skip_nulls: bool = True) -> DataFrame:
+    def sum(self, *, skip_nulls: bool = True) -> DataFrame:
         """
         Reduction returns a 1-row DataFrame.
         """
         ...
 
-    def prod(self, skip_nulls: bool = True) -> DataFrame:
+    def prod(self, *, skip_nulls: bool = True) -> DataFrame:
         """
         Reduction returns a 1-row DataFrame.
         """
         ...
 
-    def median(self, skip_nulls: bool = True) -> DataFrame:
+    def median(self, *, skip_nulls: bool = True) -> DataFrame:
         """
         Reduction returns a 1-row DataFrame.
         """
         ...
 
-    def mean(self, skip_nulls: bool = True) -> DataFrame:
+    def mean(self, *, skip_nulls: bool = True) -> DataFrame:
         """
         Reduction returns a 1-row DataFrame.
         """
         ...
 
-    def std(self, skip_nulls: bool = True) -> DataFrame:
+    def std(self, *, skip_nulls: bool = True) -> DataFrame:
         """
         Reduction returns a 1-row DataFrame.
         """
         ...
 
-    def var(self, skip_nulls: bool = True) -> DataFrame:
+    def var(self, *, skip_nulls: bool = True) -> DataFrame:
         """
         Reduction returns a 1-row DataFrame.
         """

spec/API_specification/dataframe_api/groupby_object.py

@@ -17,34 +17,34 @@ class GroupBy:
     **Methods**
 
     """
-    def any(self, skip_nulls: bool = True) -> "DataFrame":
+    def any(self, *, skip_nulls: bool = True) -> "DataFrame":
         ...
 
-    def all(self, skip_nulls: bool = True) -> "DataFrame":
+    def all(self, *, skip_nulls: bool = True) -> "DataFrame":
         ...
 
-    def min(self, skip_nulls: bool = True) -> "DataFrame":
+    def min(self, *, skip_nulls: bool = True) -> "DataFrame":
         ...
 
-    def max(self, skip_nulls: bool = True) -> "DataFrame":
+    def max(self, *, skip_nulls: bool = True) -> "DataFrame":
         ...
 
-    def sum(self, skip_nulls: bool = True) -> "DataFrame":
+    def sum(self, *, skip_nulls: bool = True) -> "DataFrame":
         ...
 
-    def prod(self, skip_nulls: bool = True) -> "DataFrame":
+    def prod(self, *, skip_nulls: bool = True) -> "DataFrame":
         ...
 
-    def median(self, skip_nulls: bool = True) -> "DataFrame":
+    def median(self, *, skip_nulls: bool = True) -> "DataFrame":
         ...
 
-    def mean(self, skip_nulls: bool = True) -> "DataFrame":
+    def mean(self, *, skip_nulls: bool = True) -> "DataFrame":
         ...
 
-    def std(self, skip_nulls: bool = True) -> "DataFrame":
+    def std(self, *, skip_nulls: bool = True) -> "DataFrame":
         ...
 
-    def var(self, skip_nulls: bool = True) -> "DataFrame":
+    def var(self, *, skip_nulls: bool = True) -> "DataFrame":
         ...
 
     def size(self) -> "DataFrame":