FEAT: Add utility to set a DataFrame to false. Eliminates bug that wi…

…ll emerge in future Pandas when setting a dataframe to False without type casting, like df.loc[:] = False.

faslr/factor.py

@@ -16,6 +16,8 @@
     TEMP_LDF_LIST
 )
 
+from faslr.utilities import df_set_false
+
 from pandas import DataFrame
 
 from PyQt6.QtCore import (
@@ -121,7 +123,7 @@ def __init__(
         # boolean values to indicate which factors in the corresponding triangle should be excluded
         # it is first initialized to be all False, indicating no factors excluded initially
         self.excl_frame = self.link_frame.copy()
-        self.excl_frame.loc[:] = False
+        self.excl_frame = df_set_false(df=self.excl_frame)
 
         # Get the position of a blank row to be inserted between the end of the triangle
         # and before the development factors

faslr/triangle_model.py

@@ -14,6 +14,10 @@
     VALUE_STYLE
 )
 
+from faslr.utilities import (
+    df_set_false
+)
+
 from PyQt6.QtCore import (
     Qt,
     QVariant
@@ -53,7 +57,7 @@ def __init__(
         self.n_rows = self.rowCount()
         self.n_columns = self.columnCount()
         self.excl_frame = self._data.copy()
-        self.excl_frame.loc[:] = False
+        self.excl_frame = df_set_false(df=self.excl_frame)
 
     def data(
             self,

faslr/utilities/__init__.py

@@ -15,6 +15,10 @@
     subset_dict
 )
 
+from faslr.utilities.dataframe import (
+    df_set_false
+)
+
 from faslr.utilities.sample import (
     auto_bi_olep,
     load_sample,

faslr/utilities/dataframe.py

@@ -0,0 +1,21 @@
+"""
+Contains commonly-used DataFrame-related routines.
+"""
+from __future__ import annotations
+
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from pandas import DataFrame
+
+def df_set_false(df: DataFrame) -> DataFrame:
+    """
+    Sets an entire DataFrame to False. Used in situations where we want a triangle of booleans where
+    we first make a copy of another DataFrame full of data (like paid loss) in order to preserve parts of its metadata
+    (accident years, development periods, etc.).
+    """
+
+    df = df.astype(bool)
+    df.loc[:] = False
+
+    return df